View clinical trials related to Anemia, Sickle Cell.
Filter by:The purpose of this research is to evaluate the effects of L-glutamine as a therapy for sickle cell anemia and sickle ß0-thalassemia. as evaluated by the number of occurrences of sickle cell crises.
This study will explore what may cause people with sickle cell anemia to have heart problems and an increased risk of sudden death. People 18 years of age and older with sickle cell anemia may be eligible for this study. Candidates are screened with a medical history and physical examination, electrocardiogram (EKG), echocardiogram (heart ultrasound), and blood tests. Participants undergo the following tests and procedures: - Holter monitoring: The patient wears a small, battery-operated device to record heart rate and rhythm over 24 to 48 hours. - QRST surface mapping: An EKG using 64 electrodes is done at rest and during exercise to provide a detailed look at the heart and its conduction system. - Chest x-rays are taken to examine the lungs. - Bicycle exercise echocardiography test: Blood pressure, pulse, heart rhythm and oxygen use are monitored while the patient exercises on a stationary bicycle. Ultrasound pictures are also obtained during the exercise. - Echocardiogram: A heart ultrasound is done to check how well the heart is pumping blood. - Pulmonary artery catheterization: A catheter (plastic tube) is inserted into a vein and advanced to the chambers of the heart, through the heart valve and into the lung artery. The pressures in the heart and lung blood vessels are measured while the patient is resting and during exercise, with the bed tilted up and down, and after giving 500 mls of fluid into a vein. - Blood tests are done to measure a hormone called brain natriuretic peptide, which can increase with the development of heart failure, and nitrite, a substance that can affect blood vessel dilation. Some blood is stored to test for inflammatory markers and for possible future gene and protein analysis. - Cardiac magnetic resonance imaging (cMRI): The patient lies in a donut-shaped magnet while pictures of the heart are obtained using a magnetic field and radio waves. Earplugs are worn to muffle the loud sounds that occur with electrical switching of the magnetic fields. A contrast agent called gadolinium may be injected to enhance the quality of the images. - Invasive electrocardiographic (reveal) monitoring: This procedure permits study of the heart rhythms over a long time period. A small device is placed just under the skin on the left side of the chest. It can be left in for up to 14 months to monitor the heartbeat continuously during this time.
This study will examine the long-term safety and efficacy of Deferasirox in patients with sickle cell disease and iron overload from repeated blood transfusions.
This study examines ways in which nitric oxide (NO), an important molecule that controls how blood flows through the body's vessels, might be restored with a compound called sodium nitrite. It is hoped that the result will reverse the effect of decreased flow of blood due to sickled cells-that is, cells that have changed into the shape of a crescent or sickle. Sickle cell disease is the most common genetic disease affecting African Americans. About 8% of that population has the sickle cell trait. The changed cells can become attached to blood vessels, decreasing blood flow to vital organs. There can be the loss of needed proteins, including hemoglobin, that deliver oxygen throughout the body. Adults at least 18 years of age who have the SS form of sickle cell disease or S-beta-thalassemia, are in either a steady state or crisis, give informed and written consent for participation, and have had a negative pregnancy test may be eligible for this study. Adults with any other disease that puts them at risk for reduced circulation are not eligible. Women who are breastfeeding are not eligible. Participants will undergo a medical history, including family medical history, and a detailed physical evaluation, to take about 1 hour. There will be a collection of blood; echocardiogram, which involves taking a picture of the heart and its four chambers; and measurement of exhaled carbon monoxide, carbon dioxide, and NO. A procedure called orthogonal polarization spectral imaging will be performed. A small object the size of a Popsicle stick will be placed under the tongue or on a fingertip. This procedure presents a picture of blood flow and how the red blood cells appear as they circulate through blood vessels. The study will be conducted in the Vascular Laboratory/Cardiovascular Floor or Intensive Care and will last about 4 hours. During the study, patients will lie in an adjustable reclining bed and chair. Small tubes will be placed in the artery and vein of the forearm at the inside of the elbow. A small pressure cuff will be applied to the wrist and a larger one to the upper arm. Both cuffs will be inflated with air. A strain gauge, resembling a rubber band, will go around the widest part of the forearm. When the pressure cuffs fill with air, blood will flow into the arm, and information from the strain gauge will be recorded. Between administrations of each medicine, there will be 30-minute rests. Normal saline will be put into the small tube in the artery. Measurements of the blood flow in the forearm will be taken, and a small blood sample will be taken to measure blood counts, proteins, and other natural body chemicals. Then a medicine called sodium nitroprusside, which causes blood vessels to expand and increase blood flow, will be placed into the forearm. It will be given at three different doses for 3 minutes each, with measurements recorded after each dose. Then a medicine called L-NMMA will be placed into the forearm. L-NMMA generally decreases local blood flow by preventing nitric oxide from being produced in the cells lining the blood vessels. It will be given at two different doses for 5 minutes each, with blood flow measured after each dose. Next, nitrite will be placed in the forearm at three different doses for 5 minutes each. Before and after nitrite is given, the researchers will measure the amount of the NO, carbon monoxide, and carbon dioxide that the patients breathe out. Then the procedure for administering normal saline, sodium nitroprusside, and L-NMMA will be repeated, as will a blood test. This study will not have a direct benefit for participants. However, it is hoped that the information gained from the study will help to develop treatment options for patients with sickle cell disease.
This study will examine whether nitric oxide (NO) gas can reduce the time it takes for pain to go away in patients who are in sickle cell crisis. NO is important in regulating blood vessel dilation, and consequently, blood flow. The gas is continuously produced by cells that line the blood vessels. It is also transported from the lungs by hemoglobin in red blood cells. Patients 10 years of age or older with sickle cell disease (known SS, S-beta-thalassemia or other blood problems causing sickle cell disease) may be eligible for this study. Patients whose disease is due to hemoglobin (Hgb) SC are excluded. Candidates are screened with blood tests and a chest x-ray to look at the lungs and heart. Participants are admitted to the hospital in a pain crisis. They are evaluated and then randomly assigned to receive one of two treatments: 1) standard treatment plus NO, or 2) standard treatment plus placebo. The placebo used in this study is nitrogen, a gas that makes up most of the air we breathe and is not known to help in sickle cell disease. For the first 8 hours of the study, patients receive placebo or NO through a facemask. The mask may be taken off for 5 minutes every hour and for not more than 20 minutes to eat a meal. After the first 8 hours, the gas is delivered through a nasal cannula (small plastic tubing that rests under the nose) that may be taken off only while showering or using the restroom. Patients are questioned about the severity of their pain when they start the study and then every few hours while they are in the hospital. Their vital signs (temperature, breathing rate, and blood pressure) and medicines are checked. Patients will breathe the gas for a maximum of 3 days, but will stay hospitalized until the patient feels well enough to go home. Patients are followed up about 1 month after starting the study by a return visit to the hospital or by a phone call.
This study will examine the effects of oral atorvastatin on the linings of blood vessels in patients with sickle cell disease, plus the agent's effect on blood markers of inflammation and blood vessel function. Sickle cell disease is a recessive genetic disorder and the most common genetic disease affecting African Americans. Inherited are abnormal genes that make hemoglobin, the substance within red blood cells that carries oxygen from the lungs to the body. In the disease, sickle hemoglobin leads to rigidity or hardness of the red cells, causing obstruction in small blood vessels, inflammation, and injury to organs when the flow of blood to them is blocked. Some medications already prescribed for other diseases, such as atorvastatin, which is used for lowering cholesterol levels, can improve blood flow. Patients 18 to 65 years of age who have sickle cell disease, who have not had an acute pain episode within the previous week, and who are not pregnant or lactating may be eligible for this study. They will undergo a complete medical history; physical examination; baseline blood tests; and echocardiogram, in which an ultrasound wand is placed against the chest wall to get images inside the heart and blood vessels. In addition, patients will have blood flow studies. During the procedure, they will lie in an adjustable reclining chair for 5 to 6 hours. There will be 20- to 30-minute rests between specific activities and blood samples will be drawn intermittently for testing. Small tubes will be placed in the artery of the forearm at the inside of the elbow. Normal saline will be infused into one tube. A small pressure cuff will be applied to the wrist and a larger cuff to the upper arm. Both cuffs will be attached to an inflation device. A device like a rubber band, a strain gauge, will be placed around the widest part of the forearm. When the pressure cuffs are inflated, blood will flow into the arm, stretching the gauge proportion to blood flow, and information will be recorded. Then light reflected from the patients' hand and the blood flow in the forearm will be measured. Activity of the genes in the white blood cells will be measured as well. Small amounts of sodium nitroprusside, widely used to reduce blood pressure in people with dangerously high blood pressure, will be injected and blood flow will be measured. Later, small amounts of acetylcholine will be injected. It usually causes blood vessels to expand. After that, small amounts of L-NMMA will be injected. It usually decreases local blood flow by blocking the production of nitric oxide in the cells lining the arm's blood vessels. Then acetylcholine combined with L-NMMA will be injected. After that, oxypurinol, an agent taken by many patients to prevent gout, will be injected. The procedures will be repeated, with oxypurinol given along with each of the agents, and the measurement of blood flow in the forearm will be measured after each drug combination. Afterward, patients will be treated for 4 weeks at home with oral atorvastatin. They will be asked to visit the Clinical Center every 2 weeks for collection of blood samples and an examination. After 4 weeks of taking atorvastatin orally, they will be asked to return to repeat the blood flow studies, but only the first half will be conducted. The part using oxypurinol will not be needed. Regarding some of the blood samples collected during the study, there will be an examination of the genes found in the white blood cells. Specific attention will go to those genes that make proteins for cell-to-cell interaction and inflammation, plus those that cause blood cells to stick to the lining of blood vessels.
The goal of this study is to determine the effectiveness of blood transfusion therapy for prevention of silent cerebral infarct (stroke) in children with sickle cell anemia.
The purpose of this study is to determine if the new orally active iron chelator, ICL670, is as safe as deferoxamine in preventing accumulation of iron in the body while a patient is undergoing repeated blood transfusions.
The purpose of this study is to compare the effects of in-home, family-administered massage and in-home relaxation training on measures of physical status and health care utilization in a sample of African American adolescents age 15 years and older and adults with chronic pain associated with sickle cell disease who have been randomly assigned to six sessions of either family-administered massage or progressive muscle relaxation training.
To use transcranial Doppler (TCD) ultrasound to detect stroke risk in children with sickle cell disease.