View clinical trials related to Sickle Cell Anemia.
Filter by:Nitric oxide is important in regulating blood vessel dilation, and consequently, blood flow. This gas is continuously produced by cells that line the blood vessels. It is also transported from the lungs by hemoglobin in red blood cells. This study will examine how this gas regulates blood vessels and blood flow in people with sickle cell anemia. It will also look at a possible benefit of using certain genetic information to compare the white blood cells of people with sickle cell anemia to those without the disease. Patients with sickle cell anemia and healthy normal volunteers 18 to 65 years of age may be eligible for this study. Candidates will be screened with a medical history, cardiovascular physical examination, electrocardiogram and routine blood tests. Participation of volunteers without sickle cell anemia will be limited to a single blood draw for genetic study. Sickle cell disease patients will undergo the following procedures: Patients will lie in a reclining chair during the study. After administration of a local anesthetic, small tubes will be inserted through a needle into the artery and vein of the patient's forearm. These are used to measure blood pressure and draw blood samples during the study. Forearm blood flow will be measured using pressure cuffs placed on the wrist and upper arm, and a strain gauge (a rubber band device) placed around the forearm. When the cuffs are inflated, blood flows into the arm, stretching the strain gauge, and the flow measurement is recorded. A small lamp will be positioned over the hand. Light reflected back from the hand provides information about nitric oxide and hemoglobin in the blood of the skin. A squeezing device called a dynamometer will be used to measure handgrip strength. Baseline blood flow, nitric oxide, hemoglobin, and handgrip will be measured after an infusion of glucose (sugar) and water. These measurements will be repeated at various times before, during and after administration of small doses of the following drugs: - Sodium nitroprusside - causes blood vessels to dilate and increases blood flow to the heart - Acetylcholine - causes blood vessels to dilate and slows heart rate - LNMMA - decreases blood flow by blocking the production of nitric oxide There will be a 20- to 30-minute rest period between injections of the different drugs. When the above tests are completed, the patient will breathe a mixture of room air and nitric oxide for 1 hour through a facemask placed over the face, after which forearm blood flow and light reflected from the hand will be measured. Then the patient will do the handgrip exercise for 5 minutes, after which blood flow and hand lamp measurements will be taken. After a 20-minute rest period (with continued breathing of room air/nitric oxide), L-NMMA will be infused again. The handgrip exercise, blood flow and hand lamp measurements will be repeated. The face mask will then be removed, and the tubes will be removed 20 minutes later. Blood samples will be collected at various times during the 5- to 6-hour study through the tubes in the arm. Some of the blood will be used to look at genes that make proteins involved in cell-to-cell communication, inflammation, and in making red and white blood cells stick to the lining of blood vessels.
OBJECTIVES: I. Phase II trial to determine surgical morbidity of decompression coring, including any adverse events in the perioperative period and the rate of secondary medical or surgical interventions. II. Collect preliminary data to determine if decompression coring results in a substantial improvement in pain and mobility compared to conservative therapy in patients with avascular necrosis of the hip related to sickle cell disease.
OBJECTIVES: I. Determine the efficacy of bone marrow transplantation using matched related donors in patients with nonmalignant hematologic disorders. II. Determine the quality of life, absence of adverse effects (e.g., graft versus host disease and B cell lymphoproliferative disease), and completeness of recovery of their underlying condition in these patients with this treatment regimen.
Sickle cell anemia is a genetic disorder that results from a single nucleotide substitution in codon 6 of the beta-globin gene which, in the homozygous state, produces an abnormal hemoglobin that is prone to polymer formation when deoxygenated. The polymerized hemoglobin leads to impaired deformability and sickling of red blood cells which subsequently lodge in end-arterioles producing the classic and most prominent feature of the disorder, repeated vasoocclusive crises. Despite knowledge of the precise genetic defect for decades, only recently has there been therapeutic impact based upon this knowledge when a clear benefit from treatment with hydroxyurea, a cell cycle-specific agent administered to induce production of fetal hemoglobin (HbF) by stimulating gamma-globin synthesis, was reported in patients with sickle cell disease (SCD). The reduction in the frequency and severity of vasoocclusive crises seen has been attributed to the increase in HbF levels in responsive patients. While the majority of patients demonstrate a rise in HbF, not all such patients benefit from treatment. Given these results, alternative agents that also stimulate the production of HbF warrant investigation in the treatment of SCD. Recombinant-methionyl human stem cell factor (SCF) is a hematopoietic growth factor with activity on immature hematopoietic progenitor cells. SCF stimulates the production of HbF in vitro and in vivo, and this effect is attainable without the myelosuppression associated with hydroxyurea. In this phase I/II trial, we will administer SCF in a dose escalating fashion to patients with sickling disorders. Parameters to be measured are HbF levels, F cell levels, peripheral blood CD34 levels, frequency, duration, and severity of vasoocclusive crises, and toxicity.
OBJECTIVES: I. Evaluate the efficacy and tolerability of fructose administered every 6 hours for up to 72 hours to patients in active sickle cell crisis. II. Obtain tolerability information in selected patients treated with fructose for more than 72 hours.
OBJECTIVES: I. Compare the efficacy of hydroxyurea with or without clotrimazole in terms of limiting the severity of anemia and the rate of hemolysis in patients with sickle cell anemia.
RATIONALE: Sickle cell disease is an inherited disorder in which abnormal, crescent-shaped red blood cells interfere with the ability of the blood to carry oxygen through the body and can cause severe pain, stroke, and organ damage. Bone marrow transplantation, is a procedure in which the soft, sponge-like tissue in the center of bones producing white blood cells, red blood cells, and platelets is replaced by bone marrow from a another person. Bone marrow transplantation may be an effective treatment in relieving the symptoms of sickle cell disease. PURPOSE: Phase I/II trial to study the effectiveness of bone marrow transplantation in treating children who have sickle cell disease.
OBJECTIVES: I. Compare the efficacy of local care alone vs local care plus arginine butyrate in terms of healing rate in patients with refractory sickle cell ulcers. II. Determine the effect of arginine butyrate therapy on tissue factors related to promotion or inhibition of wound healing in these patients. III. Determine whether the regimen used in this study is appropriate for testing in pivotal trials.
OBJECTIVES: I. Assess the efficacy of poloxamer 188 in reducing the duration of painful vaso-occlusive crisis in patients with sickle cell disease. II. Assess the effect of poloxamer 188 on duration and intensity of pain, total analgesic use, and length of hospitalization of these patients.
OBJECTIVES: Determine the effectiveness of the combined use of clotrimazole and hydroxyurea on a specific panel of red cell characteristics in patients with sickle cell syndromes.