View clinical trials related to Communicable Diseases.
Filter by:Hardening of the arteries (atherosclerosis) and heart disease are much more common in men than in women. However, as women grow older, especially after menopause the incidence of atherosclerosis and heart disease increases. These findings suggest that estrogen may be protective and help in preventing heart disease. Studies of large groups of post-menopausal women suggest that hormone replacement therapy (therapy that includes estrogen) reduces the risk of heart disease. Estrogen causes favorable changes in particles that carry cholesterol in the blood stream and improves function of blood vessels. Estrogen may also stimulate the immune system's ability to fight off infections that may lead to or contribute to atherosclerosis. Researchers believe two specific infectious agents (Chlamydia pneumoniae and human cytomegalovirus) may cause damage to the lining of blood vessels resulting in inflammation and the development of atherosclerosis. The purpose of this study is to determine if estrogen treatment can change how the immune system responds to chronic infections, by Chlamydia pneumoniae and human cytomegalovirus, in postmenopausal women.
Bacteria carry substances on their surface called antigens. When antigens come into contact with the right kinds of cells in the body an immune reaction is caused. This reaction is often the symptoms of sickness that a patient feels. In order for the body to fight off the attack of antigens, it creates substances called antibodies. Antibodies counter the action of antigens and make the bacteria harmless. However, the immune system must learn how to make the right antibodies for the right antigens. Sometimes the body creates antibodies that confuse normal tissues as foreign and attack them. This is called an autoimmune reaction and sometimes occurs when the body is exposed to certain bacteria. One bacteria known for causing autoimmune reactions is Group A beta-hemolytic Streptococcus (GABHS). This bacteria often causes throat infections commonly known as "strep throat". Some researchers believe that the autoimmune reaction associated with strep throat infections may cause neuropsychiatric disorders, like obsessive-compulsive disorder and/or tic disorder in children. As a result, each time a child with one of these disorders experiences an infection with GABHS his/her symptoms can reoccur or worsen. Researchers believe that by giving patients a certain antibiotic, they can prevent GABHS infection and thus prevent the return of symptoms. This study is designed to test the effectiveness of the antibiotic Amoxicillin for the treatment of Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS). Patients will receive Amoxicillin for six weeks and placebos "inactive sugar pills" for six weeks in order to see if the medication is truly working. Effectiveness of the treatment will be based on the presence or absence of symptoms. If at the end of the study Amoxicillin is proven to be effective treatment for PANDAS patients may be offered the opportunity to continue taking the medication for an additional six months.
This study will try to define how and where HIV infection persists in the body by determining: 1) if there are cells where HIV can live for long periods of time without being seen and destroyed by the immune system; 2) if there are sites where anti-HIV drugs cannot penetrate enough to stop new HIV replication; and 3) if HIV in certain lymph nodes can remain infectious for prolonged periods of time. It will also explore whether immune system damage caused by HIV can be repaired after new virus replication is stopped with treatment. HIV-infected patients 18 years of age and older may be eligible for this study, which will include three groups as follows. Candidates will be screened with a medical history, physical examination, blood and urine tests and possibly chest X-ray and electrocardiogram. Participants will be divided into three groups according to CD4 count levels: > 500 cells/microliter of blood; between 300 and 500 cells/microliter, and < 300 cells/microliter of blood. All participants will be treated with a combination of four antiretroviral drugs: indinavir, zidovudine, lamivudine and nevirapine. (Exceptions to this regimen may be made in certain circumstances for patients who cannot tolerate one of the four drugs.) In addition, they will undergo the following procedures: Blood tests - Blood tests will be done at screening and at study entry to evaluate the patient's health status and measure CD4 T cell count and plasma HIV levels; at the beginning of treatment to look for drug-related side effects; and during the course of the study to evaluate drug effectiveness in inhibiting HIV replication; CD4 T cell levels and function. Lymph node biopsy - Lymph node biopsies are done under local anesthesia. A small incision is made, the node is removed, and the incision is closed with stitches. Up to two nodes may be removed during each procedure. Patients with CD4 counts greater than 500 cells/microliter of blood and those with counts less than 300 cells/microliter will have three lymph node biopsies in order to 1) assess the effectiveness of therapy in inhibiting HIV replication in the nodes (the major site of replication); 2) determine how long HIV-infected cells may persist in the nodes after new replication is stopped by therapy; and 3) determine if immune damage caused by HIV can be repaired when virus replication is stopped. Lymph node biopsy in patients with counts between 300 and 500 cells/microliter of blood is required only at baseline, although follow-up biopsies are encouraged. Leukapheresis - In this procedure, whole blood is collected through a needle placed in an arm vein. The blood circulates through a cell separator machine where the white cells are removed and collected. The rest of the blood is returned to the body, either through the same needle used to draw the blood or through a second needle placed in the other arm. The collected white cells are used for special studies of the level and function of T cells before and after drug treatment. Patients with CD4 counts > 500 cells/microliter and < 300 cells/microliter will undergo leukapheresis up to four times - at study entry and about 2, 6 and 12 months after starting antiretroviral therapy. Patients with CD4 counts between 300 and 500 cells/microliter will have this procedure either at study entry and 6 and 12 weeks after initiation therapy, or on the same schedule as the other patients.
This protocol presents the rationale, 25-year historical review, and methods for multidisciplinary, low-risk studies of individuals referred to the NCI Viral Epidemiology Branch (VEB). Referrals are generally for unusual types of cancer or related conditions, known, or suspected to be related to viruses. Kaposi's sarcoma in two homosexual men evaluated in 1981 is a classic example. These referral cases provide the basis for pilot studies that generate hypotheses, the development of protocols for formal investigations of promising leads, and help to set priorities for VEB. A VEB investigator who is a Staff Member at the NIH Clinical Center, interviews each subject, performs a physical examination, draws a blood sample, and, when appropriate for the disease or virus under study, obtains other clinically indicated biological specimens, such as urine, sputum, saliva, tears, semen, Pap smear, or cervical, anal, oral, or nasal swabs. On occasion, other relatively non-invasive studies may be indicated. Skin testing with conventional, licensed antigens for assessment of cellular immunity may be performed, and skin lesions may be biopsied or excised. Tumor or other tissue biopsies may be obtained when biopsy or surgery is clinically indicated for other reasons. Otherwise no surgery is performed, and no therapy is administered. Clinical referral to other components of NCI, NIH, or the private sector are made as needed. The biological specimens are frozen or otherwise preserved to be batch tested in current assays or future assays that will be developed. Such laboratory testing is performed either at VEB's own support laboratory, or collaboratively in other NCI, NIH, or extramural laboratories that have the needed expertise for the disease or virus under study. Occasionally, repeated or more long-term evaluation is required. More often, a single evaluation in the NIH outpatient clinic, or either at a collaborating physician's office or other suitable site in the field, is sufficient. The VEB investigator provides counseling relevant to the virus or disease under study, and about the interim study results. He or she makes appropriate referral if needed (e.g., to the Genetic Epidemiology Branch for genetic counseling). Clinically relevant results and the VEB investigator's interpretation of these results, are provided in writing to the subject's primary caregiver. Confidentially of the information that is obtained is carefully protected. The results of the study are summarized for publication in the peer review literature.
Patients are exposed to infectious agents regularly, regardless of their immunologic status. Traditionally clinicians have decided to institute prophylaxis based on epidemiologic factors, skin test (i.e. PPD), or immunologic parameters. A quantitative and specific method that is non-invasive, such as quantitative PCR, would be desirable to more precisely define those who would benefit from prophylaxis. Similarly, when patients develop disease and are being treated, quantitative, non-invasive techniques are needed to assess response to therapy. This project is designed to develop and test quantitative tests using blood, urine, or sputum samples.
This protocol will follow patients who participated in NIAID's study Gene Therapy Approach for Chronic Granulomatous Diseases (95-I-0134). No further gene therapy treatments will be given under this protocol. However, because gene therapy is a new technology and involves a permanent change in the genetic code of some cells, patients who have had this treatment require long-term health monitoring. Participants will be asked to provide updated address and telephone information and the names of two contact persons, such as siblings or friends. Patients will be seen about once a year at the NIH Clinical Center to provide an update on their health status and donate a small blood sample (about 2 teaspoons), which will be frozen and stored. If a patient acquires a serious illness, such as cancer, his or her stored blood will be tested; another of blood or tissue sample may also be requested for further study. If a patient develops a medical problem that is thought possibly to be related to gene therapy, the illness will be investigated. The annual follow-up visits will continue indefinitely or until the patient declines to continue participation. Participants may also agree to store some of their blood future research on chronic granulomatous diseases and other medical conditions. Stored samples may be labeled with a code, such as a number, that only the study team can link with the patient. Any identifying information about the patient will be kept confidential as is permitted by law.
This is an open label study to determine the effects of the administration of Interferon-gamma on the clinical condition and immune function of patients with severe, treatment refractory non-tuberculosis mycobacterial infections. The study drug (interferon gamma) will be administered subcutaneously three times a week at 0.05 mg/m(2) for one year. We may also collect blood from the relatives of these patients and normal volunteers in order to characterize the genetic basis, if any, of our patients' disorders.
This study will explore faster and easier ways to detect infection with the intestinal parasite Strongyloides stercoralis and learn more about the conditions under which it causes serious disease. Ordinarily, the Strongyloides helminth (type of intestinal worm) causes only few, if any, symptoms, but in people with weakened immunity it may be very serious, and even deadly. People between 5 and 80 years of age with known or suspected S. stercoralis infection, or infection with another helminth, such as filariasis, that might cause a cross-reaction with S. stercoralis may be eligible for this study. Participants found to be infected with S. stercoralis will be treated with ivermectin, thiabendazole, or albendazole. In addition, they will undergo the following tests and procedures: - Blood tests and stool samples: Samples will be collected before and after treatment to check general health status and immune function, and to look for parasites in stool. Up to 50 milliliters (10 teaspoons) of blood will be drawn in adults and up to 25 ml (5 teaspoons) in children. - Skin tests: A test similar to those used for tuberculosis and allergies will be conducted to determine if there is sensitization to products of the parasite. Such a test might be used as a rapid method to diagnose the infection. About three drops of several different antigens (proteins) are injected into the skin of the arm. After 15 to 20 minutes, the area is checked to see if a red spot has formed and, if so, the spot is measured.
Multiple sclerosis (MS) is a disease of the nervous system. The exact cause of MS is unknown, but it is believed to be an autoimmune condition. Autoimmune conditions are diseases that cause the body's immune system and natural defenses to attack healthy cells. In the case of MS, the immune system begins attacking myelin, the cells that make up the sheath covering nerves. Without myelin, nerves are unable to transmit signals effectively and symptoms occur. This study is directed toward a better understanding of the cause of Multiple Sclerosis (MS). Researchers will evaluate patients with a tentative diagnosis of MS or other neurological diseases possibly caused by a immunological reaction. Patients will undergo a series of three MRIs, taken once a month for three months and submit blood samples for immunological studies.
Some HIV-infected adults develop lipodystrophy that includes significant changes in body shape, with fat losses in the face, arms and legs, and fat gain in the trunk. This lipodystrophy is often accompanied by other disorders of metabolism, such as increased levels of fat and insulin in the blood. The majority of these cases have been seen when patients are taking medications called protease inhibitors. These are anti-retroviral medications designed to treat patients with HIV. It is unclear if lipodystrophy is a result of having HIV or the medication used to treat HIV. It has been suggested, but not proven, that lipodystrophy is a direct side effect of protease inhibitors. In addition, it is unknown if HIV-infected children develop significant lipodystrophy after taking protease inhibitors. This study will investigate the prevalence of metabolic disorders and changes in body fat distribution in children taking protease inhibitor anti-retroviral medications. The results will be compared to three other groups; (1) children suffering from other non-HIV chronic infections, (2) HIV-infected children not taking protease inhibitors, and (3) healthy children. The study will look at HIV-infected children who have already started taking protease inhibitors. It will evaluate these children for disorders in metabolism as well as body fat changes. In addition, the study will follow HIV-infected children who will begin taking protease inhibitors. The study will follow these children for 18 months to detect the development of disorders in metabolism and / or body fat changes.