View clinical trials related to Vascular Disease.
Filter by:This is a working registry of a longitudinal cohort of Hispanics, Native Americans, and non-Hispanic whites (as controls) for tracking of vascular disease endpoints. Blood samples collected for ongoing pilot projects as well as specimen banking. Pilot studies are observational and involve risk measures for stroke, atherosclerosis, and vascular inflammatory responses. Questionnaires on demographics, risk factors, and vascular disease history are performed. No interventions proposed as yet.
This study will determine the effects of hormone replacement therapy (estrogen alone or estrogen and progesterone) on the walls of arteries in postmenopausal women. Inflammation and stiffness of artery walls are two risk factors for atherosclerosis-deposits of fatty substances (plaques) that can block the vessel, causing a heart attack or stroke. Estrogen raises the levels of certain substances in the blood that cause vessel inflammation and lowers the levels of others. This study will measure the net effects of estrogen on artery wall inflammation and stiffness. Postmenopausal women in good health may participate in this study. Volunteers will be screened for eligibility with a complete medical history, heart examination, and blood tests. Participants will be randomly assigned to receive either: 1) hormone therapy (estradiol 2 mg daily alone for women who have had a hysterectomy or estradiol plus micronized progesterone 200 mg daily for women with an intact uterus); or 2) placebo (look-alike pills that contain no active drug). Women in both groups will take pills for 3 months, then no pills for 1 month, and then will crossover to the alternate therapy for 3 months (i.e., those in the original placebo group will take hormones, and those in the hormone group will take placebo). At the end of each 3-month treatment period, participants will undergo the following procedures to assess blood vessel inflammation and stiffness: 1. Blood tests - 60 cc (about 2 ounces) of blood will be drawn to measure levels of hormones, cholesterol, and substances in the blood that indicate inflammation of the vessels. 2. Ultrasonography - an ultrasound probe will be applied gently on the neck to image the right and left carotid arteries (arteries in the neck that lead to the brain). During the procedure, the heart's electrical activity will also be monitored with an electrocardiogram and a blood pressure cuff will be wrapped around the arm to obtain blood pressure measurements every 5 minutes. 3. Magnetic resonance imaging (MRI) - Images of the carotid arteries are taken while the volunteer lies on a table in a narrow cylinder containing a magnetic field. A padded sensor called an MRI coil is placed over the neck and earplugs are placed in the ears to muffle the loud noise of the machine during scanning. During the second half of the exam, gadolinium is injected through a catheter (thin, flexible tube) inserted into a vein. Gadolinium is a contrast agent that is used to brighten the scan images. Information from this study will increase knowledge about the effects of estrogen on vessel wall inflammation. As such, it may be used in the future to help guide decisions about chronic hormone replacement therapy in postmenopausal women.
Effective treatment and prevention strategies for childhood stroke and porencephaly can only be developed once the causes are understood. There is increasing evidence that inherited and acquired coagulation abnormalities alone or in combination with environmental factors, predispose to arterial and venous thrombosis. Inherited abnormalities of factor V Leiden, prothrombin, protein C, protein S, and antithrombin III may account for many of these thromboses. At present there is little information on the existing distribution of these coagulation anomalies in children with thrombosis. Recent reports also suggest that these clotting abnormalities may be responsible for some instances of intracranial hemorrhage, porencephaly, cerebral palsy and fetal death. This study will measure the frequency of several coagulation factor abnormalities (factor V Leiden, prothrombin 20210A, protein C, protein S, antithrombin III, and antiphospholipid antibodies) in children with a history of porencephaly and stroke, and will compare these to the prevalence of these mutations in population controls and family members. We will also describe the exogenous conditions which in concert with these coagulation factors, may have led to the development of thrombosis in these children....