34 Clinical Trials for Various Conditions
Temporary mechanical circulatory support devices are increasingly used for short-term support in patients with decompensated cardiogenic shock. Recently, a new axial flow pump has become widely available with the Impella System. The Impella has been FDA approved for short term usage. Hemolysis, however, has been a common complication that has increased morbidity and mortality in this patient population. It is hypothesized that a major source of hemolysis in this patient population is shear stress experienced by red blood cells (RBC) as they travel through the pump device. In addition to causing RBC loss and potential anemia, the hemolysis has multiple other downstream consequences including creation of a pro-thrombotic environment leading to clot formation and potential device failure and secondary end organ dysfunction (renal and liver failure). Due to the significant effects of hemolysis in this population, a great deal of interest has been recently focused on addressing this problem, but as of yet no durable solutions exist. Pentoxifylline improves red blood cell deformability and reduces blood viscosity. It is hypothesized here that administering Pentoxifylline to patients in CS who require temporary MCS will decrease the amount of shear stress related hemolysis through the improved deformability and durability of RBCs. We propose to perform a double-blinded randomized controlled trial in patients who undergo an axillary Impella 5.0 insertion for acute decompensated heart failure. There will be a control group who receives a placebo and the treatment group who receives pentoxifylline. Labs will be drawn to monitor hemolysis which is our current standard protocol for the life of the device to determine the efficacy of pentoxifylline in decreasing hemolysis in this patient population.
The investigators propose to evaluate etCO in patients with HbSS, HbSC, and HbS-beta thalassemia during routine clinic visits, and longitudinally. Our goal is to know whether etCO differs amongst subjects with different sickle cell syndrome genotypes, and whether it is a stable marker of hemolytic rate, as reflected in routine labs obtained for clinical care (including total hemoglobin, reticulocyte count, lactate dehydrogenase, and, when sampled, total and direct bilirubin). We hope to establish whether this inexpensive and non-invasive test faithfully reflects hemolytic parameters in sickle cell syndromes.
The purpose of this research study is to more accurately measure the amount of true red blood cell breakdown (hemolysis) in newborn babies with potentially problematic blood type mismatch with their mothers (ABO incompatibility), and to examine how the true level of red blood cell destruction relates to other laboratory tests obtained in newborns with jaundice. A better understanding of the true amount of red blood cell destruction that is caused by blood type mismatch, as well as how it relates with other laboratory tests ordered for ABO incompatibility and red blood cell destruction, would help avoid unnecessary testing, treatment and prolonged hospital stays in such babies.
The main objective of this study is to evaluate the efficacy of danicopan as add-on therapy to a complement component 5 (C5) inhibitor (eculizumab or ravulizumab) in participants with PNH who have clinically evident EVH.
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.
People who have Sickle Cell Anemia (HbSS) produce red blood cells with shorter lifespans. These red blood cells breakdown faster, and this is called hemolysis. When red blood cells breakdown, a tiny amount of Carbon Monoxide (CO) is released into the blood and is eliminated in exhaled breath. This research study will use a device called CoSense™, which will measure Carbon Monoxide (CO) levels in breath. The purpose of the study is to see how well the device measures the CO levels that an individual breathes out.
The primary hypothesis of this study is that glutamine supplementation will improve the erythrocyte glutamine/glutamate ratio, a biomarker of oxidative stress, hemolysis and pulmonary hypertension (PH) in sickle cell disease (SCD) and thalassemia (Thal) patients with PH. PH is defined as a tricuspid regurgitant jet velocity (TRV) on Doppler echocardiography \> 2.5 m/s. We also predict that glutamine therapy will increase arginine bioavailability and subsequently alter sickle red cell endothelial interaction that can be identified using endo-PAT technology through nitric oxide (NO) generation, leading to changes in biological markers, and clinical outcome. Specifically our second hypothesis is that oral glutamine will decrease biomarkers of hemolysis and adhesion molecules, and improve the imbalanced arginine-to-ornithine ratio that occurs in hemolytic anemias, leading to improved arginine bioavailability and clinical endpoints of endothelial dysfunction and PH in patients with SCD and Thal.
This study will evaluate new treatments for people who have pulmonary hypertension, or high blood pressure in the lungs, caused by sickle cell anemia or thalassemia. Patients ages 18 and older with a diagnosis of sickle cell disease or thalassemia, who have mild to severe pulmonary hypertension, and who are not pregnant or breastfeeding may be eligible for this study. There are three stages in the study, with up to 200 participants in the screening. Patients will undergo pulmonary function tests, including those for asthma and measurement of oxygen levels in the arterial blood. They will have a chest X-ray, computed tomography (CT) scan of the lungs, ventilation perfusion lung scan to look for blood clots, echocardiogram, test to measure how far patients can walk in 6 minutes, nighttime oxygen measurement done while asleep, blood collection, magnetic resonance imaging (MRI) scan of the heart, and exercise test. About 3 to 4 days are needed for the tests, all of which can be done while patients are outpatients, except for the sleep study. For the CT scan, patients lie on a table while an X-ray beam takes images of the lungs and heart. The lung scan involves breathing of a small amount of a radioactive aerosol called Tc99m DTPA while pictures are taken of the lungs from various angles. Then an injection of albumin, a protein with a small amount of radioactivity, will be given, and more lung pictures will be taken. For the MRI scan, patients lie on a table that slides into a machine. A medication called gadolinium will be injected, to help improve images made through the scan. After the tests, patients will be admitted to the Clinical Center for 1 day. A small plastic catheter, or tube, will be placed in the vein of an arm. A longer catheter will go into a deeper vein (neck or leg), and a pulmonary artery catheter will be inserted to measure blood pressure in the blood vessels. Doctors will guide the catheter into the lung artery. Patients will be asked to pedal on a stationary bicycle while heart and lung pressure is measured. If pulmonary hypertension is present, patients will proceed to the second stage (up to 50 participants). While the catheter is still in place, patients will wear a face mask and breathe nitric oxide (NO) for 20 minutes. They will take 50 mg of sildenafil by mouth, and pressure in the heart and lungs will be monitored for about 4 hours. They will again receive NO for another 20 minutes. Blood samples will be taken, and the heart rhythm and pressure in the lungs will be monitored. Sildenafil can cause headache, flushing, and indigestion. Side effects of the lung scan involve allergic reactions to DTPA and albumin. Patients with an allergy to eggs should not have that test. Up to 25 patients can enter the third stage. They will breathe NO by using a tank of gas that delivers it through tubes to the nose, for a period of 6 weeks. They will continue taking sildenafil as previously prescribed and visit the clinic every 2 to 4 weeks for an echocardiogram, blood tests, and 6-minute walk test. After 6 weeks, patients will have catheterization of the heart again to measure pressure in the heart and lungs. Then NO will be stopped, and pressure in the lungs will be checked to see if NO has helped lower the blood pressure-and to make sure that the blood pressure does not increase when medication is stopped. Patients whose symptoms have improved as a result of breathing NO may wish to continue with that therapy.
Background: * Probiotics are oral food supplements containing live bacteria that may be beneficial to a person s digestion or general health. Probiotics are available as tablets, powder, or liquid supplements and are frequently used to supplement yogurt. They are available for purchase without prescription in most supermarkets. * The bacteria in probiotic supplements commonly express sugar substances on their surface. These sugar substances are similar to group A and B blood group sugars, called antigens. These antigens determine a person s blood group. Researchers are studying the effect of probiotic supplements on the amount of blood group antibodies that are present in a person s blood. Objectives: * To determine whether taking oral probiotic supplements increases anti-A and anti-B isoagglutinins (antibodies that cause red blood cells to clump together) in healthy subjects. * To study the frequency of these effects and determine whether there is a dose-response relationship with probiotics and isoagglutinin titers. Eligibility: * Healthy adults, 18 years or older, with type A, B, or O blood. * Female participants need to have undergone menopause or have had a hysterectomy. * Individuals are ineligible if they currently donate platelets; have a history of ulcerative colitis or Crohn s disease; have had major bowel surgery; are pregnant or capable of becoming pregnant; have a bleeding or clotting disorder; have a history of a blood disorder or immune deficiency; have a history of high-risk behaviors for exposure to HIV or hepatitis B or C; have diabetes; have received vaccinations in the past 2 months, with the exception of the flu vaccine; are currently taking immunosuppressive medications; are currently taking antibiotics; or have taken probiotic supplements within the last 12 months. Design: * Researchers will conduct the following tests throughout the 28-week study: * Blood samples will be drawn every 2 weeks to measure the quantity of isoagglutinin titers. * Depending on individual results, continued blood testing may be done every 3 months for 1 year, then every 6 to 12 months for up to 5 years. * Study subjects will take a probiotic supplement at a dose of 1 to 3 caplets per day for 18 consecutive weeks according to the following schedule: * During the first 6-week period, the subject will take one probiotic tablet daily. * During the second 6-week period, the subject will take one probiotic tablet twice daily. * During the third 6-week period, the subject will take one probiotic tablet three times daily. * Control group subjects will be followed in a similar manner but will not take probiotic supplements. * The outcome measure is the percent of probiotic ingestors (the study subjects) versus control group subjects who experience a fourfold or greater rise in isoagglutinin titer. * Study subjects will receive the following financial compensation: $10 per blood sample, for a maximum of $240 if all 24 samples are collected; $100 after completing the first 6-week period; $150 after completing the second 6-week period; and $200 after completing the third 6-week period. * Control subjects will receive $10 per blood sample, for a maximum of $150 if all 15 samples are collected.
This study aims to learn more about blood management in children undergoing heart surgery, such as the right amounts, and the best blood products, to administer. It also aims to develop a mathematical model that may help researchers better predict and treat patients who need blood transfusions during heart surgery.
The objective is to determine the effectiveness of pulsatile flow during cardiopulmonary bypass to reduce the incidence of acute kidney injury after cardiac surgery. Investigators will also evaluate the safety and impact of pulsatile flow on clinical outcomes compared to non-pulsatile flow during cardiopulmonary bypass.
Left ventricular assist device (LVAD) patients remain at risk for pump thrombus and thromboembolic events through multiple mechanisms. The HeartWare® Ventricular Assist System (HVAD®, HeartWare Inc., Framingham, MA, USA) includes a novel speed modulation feature called Lavare™ cycle. The Lavare™ Cycle is aimed to promote washing of left ventricle to decrease blood stasis and subsequent risk of thrombus formation, ingestion and/or expulsion. No prior study has prospectively evaluated the impact of Lavare™ cycle on patient outcomes in a randomized fashion. We intend to assess effects of Lavare™ Cycle among patients receiving HVAD LVAD in this randomized controlled pilot project.
The investigators propose a randomized study to compare bovine carotid artery (BCA) biologic grafts and expanded polytetrafluoroethylene grafts (ePTFE) for permanent hemodialysis access.
The advent of continuous flow (CF) pumps for patients with severe heart failure has led to marked improvements in survival; however, pump operation remains fraught with adverse thrombotic events. This climbing rate of thrombosis and stroke during CF pump support has led to a recent warning by the US Food and Drug Administration. Despite a rising incidence of pump thrombosis and its downstream complications of stroke, the hematologic mechanisms behind these devastating adverse events remain uncertain. Recently, it has been recognized that CF pump induced hemolysis precedes and is associated with thrombosis. In-vitro studies show increased platelet function with exposure to products of hemolysis, which is also known to occur in diseases of intravascular hemolysis such as sickle cell anemia. This proposal will investigate if hemolysis associated increased platelet function can be reduced by a potentiation of nitric oxide signaling by an oral phosphodiesterase-5 inhibitor, sildenafil. Elucidating mechanisms of hemolysis induced thrombosis may inform best strategies for prevention of end organ damage and maintaining optimal CF pump operation.
The objective of this study is to assess if prolonged storage time of a packed red blood cell unit may cause pulmonary vasoconstriction after transfusion, in a susceptible population such as cardiac surgery patients. The investigators will also evaluate the potential reversal effect of Inhaled Nitric Oxide on pulmonary vasoconstriction induced by stored blood transfusions.
This study will try to determine what causes toxic side effects of stem cell transplantation, such as increased blood pressure, increased heart rate, decreased kidney function and abnormal heart rhythms. Stem cells are used to treat various diseases, including cancer, aplastic anemia and sickle cell disease. The cells may be given fresh to the patient or they may be preserved first with a chemical called DMSO and frozen for later use. Some stem cell transplant procedures include infusion of red blood cells along with the stem cells. This study will examine whether side effects of stem cell transplants are associated with the DMSO preservative in frozen cells or with hemoglobin (a protein released from defrosted red blood cells) or neither of these factors. Healthy volunteers and patients scheduled to receive a stem cell transplant may be eligible for this study. Candidates must be between 10 and 80 years of age. Transplant patients will undergo a stem cell transplant. The cells are infused through a catheter placed in a vein for the procedure. Depending on the patient s requirements, the infusion may or may not include red blood cells and may or may not contain DMSO. Healthy volunteers undergo a 4-hour saline infusion. The saline (water mixed with salt) is infused through a catheter (plastic tube) placed in a vein in the arm. In addition, all participants have the following tests and procedures: * Heart monitoring: Healthy volunteers wear a portable heart monitor, attached to the chest using four stickers, for 24 hours starting the morning of the infusion. Transplant patients wear the same device for 48 hours, starting the morning before the infusion. * Blood draws and urine collections before, during, just after and the morning after the infusion of saline or stem cells. * Heart ultrasound before, during or just after and the morning after the infusion. * Peripheral artery tonometry: A small cup is placed on one finger of each hand to measure blood flow in the finger. A blood pressure cuff is inflated around the lower arm and tight pressure is maintained for about 5 minutes.
This study will examine blood for factors that may cause or prevent diseases involving iron or red blood cells. Iron is an important nutrient for human health that is needed to produce red blood cells. Red blood cells carry oxygen to body tissues. A better understanding of iron and red blood cells may help lead to better treatment of several diseases including anemia. Patients of all ages with red cell abnormalities in the following categories may be eligible for this study: * Diseases with deficiency, overload or maldistribution of iron * Known red blood cell diseases, such as anemias and hemoglobinopathies * Red blood cell diseases of unknown cause, such as hemolysis of unknown cause * Red blood cell abnormalities with no overt clinical disease, such as hereditary persistence of fetal hemoglobin Participants undergo the following procedures: * Medical history * Physical examination * Standard medical tests related to the individual's iron or red blood cell condition Blood draw for the following purposes: * Testing for syphilis and for the hepatitis B and C, HIV, and HTLV-1viruses, and for a pregnancy test for women who can become pregnant * Research purposes. This blood is analyzed for genes, proteins, sugars, and fat molecules.
The researchers are testing a medication named ravulizumab for the treatment of severe preeclampsia and Hemolysis, Elevated Liver enzymes, Low Platelets (HELLP) syndrome.
This study is a single center, prospective, cross-over phase 1 trial. Eighteen subjects will be enrolled in the study evaluating the metabolism, pharmacokinetic behavior and tolerability of primaquine enantiomers and placebo over the course of 5 days.
To investigate the comparative tolerability, metabolism and pharmacokinetics of individual enantiomers of PQ in healthy human volunteers, receiving study drug over the course of 7 days.
Acute kidney injury is a major complication of cardiac surgery requiring cardiopulmonary bypass (CPB). Hemolysis and rhabdomyolysis frequently occur during CPB. Hemolysis leads to an increase in free hemoglobin, whereas rhabdomyolysis leads to an increase in myoglobin. Free plasma hemoglobin and myoglobin have been shown to be independent predictors of the acute kidney injury that results from CPB. When these hemeproteins are released into the plasma, they undergo redox cycling, generating radical species that initiate lipid peroxidation and a cascade of oxidative damage to cellular membranes, notably in the kidney. F2-isoprostanes and isofurans are sensitive and specific markers of oxidative stress in vivo, and are increased after CPB, particularly in those patients with acute kidney injury. Acetaminophen inhibits the lipid peroxidation catalyzed by myoglobin and hemoglobin. Moreover, in an animal model of rhabdomyolysis-induced kidney injury, acetaminophen significantly attenuated the decrease in creatinine clearance compared to control. The current proposal tests the central hypothesis that acetaminophen will attenuate the lipid peroxidation associated with the hemolysis and rhabdomyolysis that occur in patients undergoing CPB. Demonstration that acetaminophen inhibits the lipid peroxidation resulting from CPB would provide a rationale for a prospective randomized trial to test the hypothesis that acetaminophen will reduce the acute kidney injury that results from CPB.
Background: - Chronic leg ulcers are a complication of many blood disorders such as sickle cell disease, thalassemia, and other red blood cell disorders. In these disorders, red blood cells break down earlier than normal, which researchers suspect may cause or contribute to the development of leg ulcers; however, the exact cause is unknown, and current therapies are not very effective. Researchers are interested in determining if a research cream made with sodium nitrite, a substance that is known to increase blood flow by dilating blood vessels, may speed up the healing of skin ulcers. Objectives: - To evaluate the safety and effectiveness of topical sodium nitrite cream as a treatment for chronic leg ulcers in individuals with sickle cell disease or other red blood cell disorders. Eligibility: - Individuals at least 18 years of age who have sickle cell disease or another red cell disorder and have had a leg ulcer for more than 4 weeks. Design: * Participants will be screened with a physical examination, medical history, blood tests, and an examination of the ulcer, including x-ray of the leg(s) with the ulcer and swabs from the wound. * Participants will be scheduled for a 5-day inpatient stay at the Clinical Center, with the following procedures: * Days 1 and 2: Participants will have blood draws, a wound assessment, ultrasound of the affected leg, imaging studies (magnetic resonance imaging and infrared photography), thermo-patch application to monitor temperature changes, measurements of blood flow in the skin, and questionnaires about pain and quality of life. An optional skin biopsy may also be conducted with samples taken near the skin ulcer * Day 3: Participants will have one ulcer treated with the topical cream. Frequent blood draws will be conducted before application and then regularly for up to 6 hours after application of the cream. Thirty minutes after the research cream is applied, participants will have imaging studies of the treated leg and measurements of pain levels and blood flow. * Day 4: Participants will have a blood draw and temperature recordings taken. * Day 5: Participants will have the research cream applied and the same imaging studies as before, and will be discharged for care at home. * For the following 3 weeks, participants will come to the clinical center twice a week to have the research cream applied to the leg ulcer and tests performed by the study researchers. * For the fourth and final week, participants will return for additional cream treatment sessions, imaging studies, blood draws, and other tests as directed by the study researchers. * Study participation will end in the following week (week 5). Subjects will come for a final visit one month after the end of the study.
The current proposal tests the central hypothesis that acetaminophen will attenuate the oxidative stress response associated with cardiopulmonary bypass (CPB)-induced hemolysis in children undergoing cardiac surgery.
It is a normal process in the human body for red blood cells to die, which makes bilirubin. Bilirubin is cleared away through the liver. Some babies are born with livers that don't work well enough yet, or their red blood cells are dying too fast, so the baby looks yellow (jaundice). This means there is too much bilirubin in the body. It can be dangerous if a baby's bilirubin gets too high. Phototherapy is what they call the lights they shine on newborn babies to help the liver get rid of bilirubin. This study tests an experimental drug to see if it can reduce how much bilirubin is being made in the first place.
In this prospective observational trial, participants with chronic hemolysis will be assessed with echocardiogram for elevated tricuspid jet velocity and other evidence of pulmonary hypertension. Participants will have laboratory studies evaluating: severity of hemolysis, splenic function, inflammation, endothelial dysfunction, and hypercoagulability. There will be 3 main categories of participants enrolled in this study: (1) pediatric participants with severe sickle cell disease (SCD) (HbSS, HbS/β° thalassemia ) who are not receiving treatment (e.g., hydroxyurea or chronic transfusions); (2) pediatric participants with other forms of SCD or severe SCD (HbSS, HbS/β° thalassemia) patients being treated with hydroxyurea or chronic transfusions; and (3) pediatric and adult participants with other non-sickling hematological disorders.
This study will examine the effectiveness of S-adenosyl methionine (SAMe) in combination with peginterferon and ribavirin for treating hepatitis C virus. One out of three patients with hepatitis C develops cirrhosis of the liver, which can lead to liver failure or liver cancer. SAMe is a nutritional supplement that is made naturally in all cells of the body and acts to improve how the body handles stress. In laboratory experiments with liver cells, SAMe decreases the injury caused by liver toxins and improves the ability of interferon to block hepatitis C virus. Patients 18 years of age and older with hepatitis C infection who did not respond successfully to prior treatment with interferon and ribavirin or peginterferon and ribavirin may be eligible for this study. Participants receive the following treatment: * Peginterferon (given by injection) and ribavirin (taken by mouth) for 2 weeks * Washout period (no medications) for 4 weeks * SAMe (taken by mouth) for 2 weeks * Peginterferon, ribavirin and SAMe for 12-48 weeks, depending on patient response to treatment. Participants have a thorough physical evaluation before beginning treatment and again at the study's end. After starting treatment, patients return for clinic visits and blood tests weekly for the first several weeks, then less frequently (at 2-week, then 4-week and 8-week intervals until up to 72 weeks) to monitor symptoms, drug side effects, hepatitis C virus levels, liver enzyme levels and immune responses to hepatitis C. ...
This study will evaluate a new and safe testing method for identifying medicines that can cause problems in glucose-6-phosphate dehydrogenase (G6PD) deficient individuals. We are looking for volunteers with G6PD deficiency who would be willing to donate blood samples.
This study will examine the effectiveness of low-dose peginterferon and ribavirin therapy for certain patients with chronic hepatitis C-a liver disease that, in some patients, can progress to cirrhosis of the liver, liver cancer, and liver failure.
This study will examine blood cells of patients with paroxysmal nocturnal hemoglobinuria (PNH) after they receive a blood transfusion to determine if certain proteins (GPI-linked proteins) in the transfused blood transfer to the patient's blood cells. GPI-linked proteins, which are normally present on red cells and regulate red cell survival, are absent in patients with PNH. Their lack is believed to account for the premature destruction of red blood cells in these patients, resulting in a low hemoglobin and hematocrit. Patients may experience fatigue, flank pain and other symptoms, requiring treatment with blood transfusion. Patients with PNH 18 years of age or older with group A1 blood who require at least three units of red cells and who have not been transfused with group O blood within the last 3 months may be eligible for this study. Participants will come to the NIH Clinical Center for the following procedures: * Interview about the severity of their anemia-related symptoms * Blood test * Blood transfusion, if required. Patients will be transfused with compatible group O blood. The donor blood will be washed (rinsed with a salt solution) until it is 99% free of donor plasma. Group O blood is given instead of group A1 in order to be able to distinguish the patient's cells from the transfused cells. Blood samples of 3 teaspoons each will be drawn 1 day, 1 week, and 3 weeks after the transfusion. These samples may be collected by the patient's doctor locally and sent to NIH by mail. If it is found that GPI-linked proteins transfer to the patient's cells, the study will also examine how long the proteins remain attached and will assess whether the proteins are functional and prevent cell destruction.
This study will examine the effectiveness of pegylated interferon, or peginterferon (a long-acting form of alpha interferon) plus ribavirin in treating hepatitis C (genotype 1) infection with and without kidney disease.