92 Clinical Trials for Various Conditions
Anesthetic preconditioning (APC, a brief exposure to an anesthetic gas) has become an area of intense research interest because of its ability to protect tissue and organs from injury resulting from a cessation of blood flow and then a re-establishment of flow. The blood vessel lining plays a key role in this injury. This research will examine, in human volunteers, several important modifiers of APC in human blood vessels: high blood sugar, vitamin C, and statin drugs. Thus, the proposed studies will advance the investigators' understanding of mechanisms of this injury in humans and explore important modifiers of APC protection from injury.
The overall hypotheses of this project is that severe sepsis is associated with endothelial dysfunction; that endothelial dysfunction, in turn, is predictive of subsequent organ failure and death; and that protocolized resuscitation attenuates endothelial cell (EC) dysfunction and improves patient survival.
To understand how AKI (Acute Kidney Injury) leads to chronic kidney disease so therapies can be found to alter the progression of events thereby significantly impacting the long-term outcomes of children who develop AKI.
To determine what proportion of patients have inferior angle recess dimensions that could accommodate the OTX-TIC, and what are risk factors for implant contact with the corneal endothelium.
The Vendys II, an FDA-approved device, uses finger digital thermal monitoring (DTM) after a period of blood flow restriction to evaluate vascular health. This study will evaluate the feasibility of using this device to measure the Vascular Reactivity Index (VRI) in children and adolescents/young adults (AYA) undergoing hematopoietic cell transplantation (HCT).
This study is an ancillary (add-on) study to the clinical trial entitled "Effect of Nitric Oxide in Cardiac Surgery Patients With Endothelial Dysfunction", which has Clinical Trials.gov identifier NCT02836899. NCT02836899 trial randomizes cardiac surgical patients to receive either Nitric Oxide (NO) or a placebo during and after cardiac surgery. This ancillary study aims to assess the effects of Nitric Oxide on vascular responsiveness and on endothelial function during hemolysis in patients with pre-operative endothelial dysfunction undergoing cardiac surgery requiring prolonged cardiopulmonary bypass.
The purpose of this study is to test the effects of a one time dose and 7-days of inorganic nitrate (supplied in the form of beetroot juice) on blood vessel function and resting blood pressure in healthy, postmenopausal women. Participants will drink beetroot juice and a placebo juice on separate visits where blood pressure and blood vessel function will be measured.
Determination of the acute pulmonary toxicities of e-cigarettes in young adults is of major public health importance, as e-cigarette vapor contains established toxicants that as hypothesized cause acute damage to the airways and the pulmonary microvasculature that may promote the development of CLD, for which there remain few effective therapies. The study therefore propose a pilot study using a randomized crossover design in ten healthy young adults to test the acute effects of a standardized e-cigarette exposure on two sensitive, safe, non-invasive imaging measures: (1) ventilation defects on hyperpolarized helium-enhanced magnetic resonance imaging, and (2) pulmonary microvascular blood flow on gadolinium-enhanced pulmonary magnetic resonance angiography.
In this study, the investigators will test the hypothesis that acute in vivo exposure to hyperglycemia increases mitochondrial network fragmentation and mitochondrial reactive oxygen species production (ROS) production in human arterial endothelial cells.
The primary purpose of this study is to evaluate the acute effects of electronic cigarette (e-cigarette) smoking on measurable biomarkers of platelet function, vascular endothelial function and inflammation in healthy active smokers. 10 healthy subjects, smokers, with no other medical conditions will be included in this study and measurements will be obtained at baseline and after smoking an e-cigarette. The study will contribute to the understanding of the effects of e-cigarettes on cardiovascular physiology, specifically establishing if the use of e-cigarettes increases platelet aggregation and platelet activation when compared to baseline in healthy active smokers, if the use of e-cigarettes decreases brachial artery flow-mediated dilation compared to baseline in healthy active smokers, and to determine the association between biomarkers of inflammation, platelet function, and vascular endothelial function before and after use of e-cigarettes.
In HIV+ cigarette smokers, with no prior history of pulmonary infections, emphysema is often developed at an earlier age and is a significant cause of morbidity despite treatment with antiretroviral drugs. Preliminary data gathered from HIV+ individuals that smoke cigarettes strongly support the hypothesis that the combination of HIV infection and smoking creates increased stress in the lower respiratory tract. To examine the underlying factors that contribute to the accelerated development of emphysema in this cohort, samples from the lower respiratory tract will be provided by HIV+ and HIV- subjects. The samples collected will serve as biomarkers for assessing the onset of emphysema.
The purpose of this project is to see if heritable alterations in the function, biology and vascular repair capacity of vascular cells make a major contribution to the burden of coronary artery disease (CAD), fibromuscular dysplasia (FMD), and other vascular diseases. In more detail, FMD is a nonatherosclerotic vascular disease that primarily affects women aged 20 to 60. It commonly affects the renal and carotid arteries but may involve almost every artery in the body. At the cellular level, FMD is characterized by increased fibroblast proliferation and collagen deposition. This study aims to define some of these cellular problems by directly studying fibroblast cells from FMD patients and healthy control subjects. Similarly, CAD is among the leading causes of death worldwide. However, a large part of the risk for CAD is unexplained. It is thought that a major but undefined risk factor may be gene (genomic) variations causing a change in vascular cell function. Here, we will study important vascular cell types in patients with severe and early onset CAD in an attempt to define these problems. Therefore, in summary, this study will look to define the various cellular-level problems that occur in patients with both in CAD and FMD. These data will be linked to DNA-level analyses to ultimately attempt to define the cause of these conditions.
The purpose of this study is to determine the effect of music therapy before, during, and after cardiac catheterization is associated on (a) change in reactive hyperemia index measured before and after catheterization using peripheral arterial tonometry and (b) patient stress and discomfort measured by a questionnaire, as compared to the standard of care (no music during cardiac catheterization). The hypothesis of the study is that music therapy during cardiac catheterization will be associated with more favorable change in reactive hyperemia and higher patient satisfaction compared to no music playback.
This study was conducted because the FDA requested clinical information on potential effects of intravitreal injections of Macugen (pegaptanib sodium injection) on the corneal endothelium from a 1-year (minimum) post-approval clinical study to support that there are no adverse effects on the corneal endothelium following intravitreal injections of Macugen.
The investigators will test the hypothesis that markers of vascular endothelial dysfunction will be exaggerated acutely with an extreme high sodium diet compared to an extreme low-sodium diet. The investigators will compare patients with postural orthostatic tachycardia (POTS) to healthy control subjects.
This is a single center prospective study of 30 patients undergoing elective heart bypass surgery (CABG) with at least two vein grafts from the leg (SVG). The purpose of this ex vivo study is to evaluate the function of vein grafts from small tissue samples treated with a pressure syringe and a non-pressure syringe. Syringes are routinely used to flush out the veins in preparation of bypass grafting. It is unknown if different levels of pressure in the syringe affect the vein or damage the vein. Small sections of tissue samples which are normally discarded will be obtained immediately after retrieval from the leg and before grafting to the heart. Tissue samples will be taken to the laboratory for study. There are no clinical endpoints in this study, however, clinical information will be obtained from the Society of Thoracic Surgeons database and will include demographics, risk factors, and perioperative outcomes.
This study will test the hypothesis that uric acid impairs the function of vessels in patients with kidney disease
Improvement in cardiovascular mortality is related to changes in pathologic autoantibodies and in the number of circulating functional replicative competent endothelial progenitor cells (EPC's) after bariatric surgery.
The purpose of this study is to determine whether the surgical outcomes in patients undergoing Descemet's Stripping Endothelial Keratoplasty (DSEK) are improved with the use of an insertion device over the traditional forceps insertion method.
The objective of the study is to assess how DisCoVisc Ophthalmic Viscosurgical Device (OVD) compares with Healon and Amvisc Plus in the protection of corneal endothelial cells, and the ability to maintain anterior chamber space, in routine cataract surgery.
A study of 12 weeks' treatment with losartan or placebo, to test the hypothesis that RAS inhibition will improve insulin' vascular actions and therefore improve insulin sensitivity in skeletal muscle.
Doctors will take some tissue from the tissue removed during surgery in order to study how the blood vessels of the tumor respond to radiation therapy. The tissue obtained will be used to determine how these tumor blood vessels respond to radiation therapy delivered to the tumor, after it has been removed. This radiation is delivered in the research lab. This research is being conducted in order to develop new methods to treat tumors by radiation therapy. No additional surgery will be performed to obtain these samples, and only materials that remain after all diagnostic testing has been completed will be used.
Nitric oxide (NO) is a soluble gas, continuously synthesized by the endothelium, that contributes importantly to vasodilator tone of the coronary and systemic circulations by activating guanylyl cyclase in vascular smooth muscle, causing relaxation. Although regional synthesis of NO by the endothelium contributes to local vasodilator tone, Stamler and co-workers have proposed that regional vascular tone may also be regulated by NO transported from the lungs by hemoglobin as a consequence of enhanced binding of NO to reactive thiols of oxygenated hemoglobin. This study is designed to determine the contribution of hemoglobin-transported NO to forearm microvascular dilator tone in healthy subjects at rest and during regional hypoxia associated with forearm exercise stress, with measurements made before and after regional blockade of endothelial NO synthesis. Findings in this study may be relevant to understanding the physiological contribution and therapeutic potential of hemoglobin-transported NO in the regulation of vasodilator tone in diseases and conditions associated with regional endothelial dysfunction and reduced endothelial NO bioactivity (e.g., hypertension, diabetes mellitus, hypercholesterolemia, cigarette smoking, and estrogen deficiency).
Trauma-induced coagulopathy is a central cause of preventable deaths from hemorrhage after injury. The contribution and impact of altered post injury platelet biology on trauma-induced coagulopathy is not well understood despite the pivotal contribution of platelets to normal coagulation and endothelial integrity. The central hypothesis for this study is that severe injury and shock drive altered platelet activation, platelet aggregation, and platelet-endothelial interactions that are associated with increased rates of transfusion, organ failure, and mortality. This study will investigate these causal pathways, mechanisms, and associated outcomes in a prospective observational trauma cohort through collection of biospecimens and detailed clinical data.
Nitric oxide gas is important in regulating blood vessel dilation, and consequently, blood flow. This gas is continuously produced by endothelial cells, which line the blood vessels. This study will examine whether nitrite, a molecule that normally circulates in the blood stream, can also dilate blood vessels. The results of this study may be valuable in developing treatments for people with conditions associated with impaired endothelial production of nitric oxide, including high blood pressure, high blood cholesterol, diabetes, estrogen deficiency, and others. Healthy, non-smoking normal volunteers 21 years of age or older may be eligible for this study. People who lack the enzyme G6PD or cytochrome B5 in their red blood cells may not participate. Absence of these enzymes can lead to episodes of sudden shortness of breath and cyanosis (blueness of the skin due to lack of sufficient oxygen). Participants will undergo the procedures described in study Parts A and B, as follows: * Part A - After numbing the skin, small tubes are placed in the artery and vein at the inside of the elbow of the dominant arm (right- or left-handed) and a small tube is placed in a vein of the other arm. The tubes are used for infusing saline (salt water) and for drawing blood samples. A pressure cuff is placed around the upper part of the dominant arm, and a rubber band device called a strain gauge is also placed around the arm to measure blood flow. When the cuff is inflated, blood flows into the arm, stretching the strain gauge at a rate proportional to the flow. Grip-strength of the dominant arm is measured with a dynamometer to determine maximum grip-strength. Then, several measurements of blood flow, nitrite, hemoglobin, and handgrip are made before and after administration of L-NMMA, a drug that blocks endothelial production of nitric oxide. * Part B - Part A testing is repeated, except that sodium nitrite dissolved in a saline solution is infused into the artery of the forearm for a few minutes before and during the hand-grip exercises. In addition, blood samples are drawn before and after each handgrip exercise to measure methemoglobin, a substance that, at excessive levels, can cause adverse side effects.
Prolonged periods of reduced activity are associated with decreased vascular function and muscle atrophy. Physical inactivity due to a sedentary lifestyle or acute hospitalization is also associated with impaired recovery, hospital readmission, and increased mortality. Older adults are a particularly vulnerable population as functional (vascular and skeletal muscle mitochondrial dysfunction) and structural deficits (loss in muscle mass leading to a reduction in strength) are a consequence of the aging process. The combination of inactivity and aging poses an added health threat to these individuals by accelerating the negative impact on vascular and skeletal muscle function and dysfunction. The underlying factors leading to vascular and skeletal muscle dysfunction are unknown, but have been linked to increases in oxidative stress. Additionally, there is a lack of understanding of how vascular function is impacted by inactivity in humans and how these changes are related to skeletal muscle function. It is the goal of this study to investigate the mechanisms that contribute to disuse muscle atrophy and vascular dysfunction in order to diminish their negative impact, and preserve vascular and skeletal muscle function.
Prolonged periods of reduced activity are associated with decreased vascular function and muscle atrophy. Physical inactivity due to acute hospitalization is also associated with impaired recovery, hospital readmission, and increased mortality. Older adults are a particularly vulnerable population as functional (vascular and skeletal muscle mitochondrial dysfunction) and structural deficits (loss in muscle mass leading to a reduction in strength) are a consequence of the aging process. The combination of inactivity and aging poses an added health threat to these individuals by accelerating the negative impact on vascular and skeletal muscle function and dysfunction. The underlying factors leading to vascular and skeletal muscle dysfunction are unknown, but have been linked to increases in oxidative stress. Additionally, there is a lack of understanding of how vascular function is impacted by inactivity in humans and how these changes are related to skeletal muscle function. It is our goal to investigate the mechanisms that contribute to disuse muscle atrophy and vascular dysfunction in order to diminish their negative impact, and preserve vascular and skeletal muscle function across all the lifespan.
The goal of this clinical trial is to determine the effect of elevated plasma ceramides on peripheral vascular function. Subjects will consume a high fat meal consisting of long chain fatty acids (to increase plasma ceramides) or medium chain fatty acids (control). Subjects' vascular function will be assessed with laser Doppler flowmetry to measure their artery function and with the CytoCam device to assess their peripheral microvascular endothelial function.
High sodium diets impair vascular function, which may influence the work of the heart. This investigation is designed to determine if this change in vascular function results in a greater workload in the heart and if people who regularly exercise are protected from these effects.
The purpose of this research study is to see the effect of taking Aged Garlic Extract (AGE) on the progression of coronary plaque, a condition called atherosclerosis, in people diagnosed with Diabetes.