4 Clinical Trials for Various Conditions
This study will test whether 42 days of cannabis abstinence, compared to continued cannabis use, is associated with improvements in cognition and psychiatric disorder symptoms. Identical twins, who are concordant on cannabis use, will be experimentally-manipulated to be discordant for 42 days. Each twin, within a twin pair, will be randomly assigned to either the contingency management condition, incentive-based protocol to promote cannabis abstinence, or control condition, no changes in cannabis use requested.
Somatic mosaicism in cancer associated genes is one potential explanation for discordance in childhood cancer that has not been fully explored to date. This pilot study will focus on twins with central nervous system (CNS) tumors who are identified through the Children's Oncology Group's Project: EveryChild (PEC) registry or volunteer.
The definition of the most 'at-risk' population within highly susceptible groups would provide an opportunity for preemptive therapeutics. A convenient, safe, and tolerable therapy that delays the onset of clinical disease during the pre-symptomatic stage of demyelinating disease would provide a therapeutic alternative to a 'wait and see' approach in subjects at 'high risk' for CIS (clinically isolated syndrome - monosymptomatic demyelinating disease) or MS. Identical twins share the same genes and have the highest rate of shared MS. An identical female with a sister twin with MS has a 34% chance of having MS. Non concordant (no MS yet) identical (monozygotic - from the same sperm-egg zygote) female twins provide an ideal population to find out what factors predict the onset of MS in the non-affected twin. We will recruit 30 identical female twins, one with MS and the other without MS, and obtain brain MRI and biological samples on the non-affected twin and determine if: * the presence of characteristic MS-like lesion(s) on baseline MRI predisposes to MS. * specific proteins in blood or cerebrospinal fluid predispose to the clinical expression of demyelinating disease If we can predict by simple tests (MR brain scan and blood tests) the likelihood of the onset of MS in 'at risk' subjects, and have safe and tolerable therapies, we may be able to prevent the clinical onset of demyelinating disease (MS).
This study will examine families in which one sibling of a sibling pair, or twin pair, has developed a systemic rheumatic disease and one has not, to see if and how the two differ in the following: * Blood cell metabolism; * Types of cells in the blood; * Environmental exposures or genetic factors that might explain why one developed disease and the other did not. Families in which one sibling has developed a systemic rheumatic disease, rheumatoid arthritis, systemic lupus erythematosus, scleroderma, dermatomyositis, or myositis, and the other has not, are eligible for this study. The siblings may or may not be twins, but must be of the same gender and be within a 5-year age difference. Biological parents, or, in some cases, children, will also be included in the study. Normal, healthy volunteers will serve as control subjects. Participants will undergo some or all of the following tests and procedures: * Medical history and physical examination. Participants will also be asked permission to obtain medical records for review. * Questionnaires about environmental exposures at work, at home, and elsewhere. Probands (participants with rheumatic disease) and their healthy siblings will also answer questions about infections, vaccinations, medications or dietary supplements, sun exposure, and stressful events during the year before disease diagnosis in the affected sibling. * Blood and urine collection for the following tests: * Routine blood chemistries and other studies to rule out certain diseases or medical problems; * Evidence of past toxic exposures and certain infections; * Presence of cells from the mother in the child s blood and vice versa. (Recent studies suggest that during pregnancy or delivery, cells from the mother and baby may be exchanged and circulate in the body for many years, possibly causing problems); * In twin or sibling pairs, presence of certain genes that may be more common in patients with systematic rheumatic diseases as compared with their unaffected siblings and normal volunteers; * In identical twins, comparison of their blood cell metabolism to see if and how the metabolism differs in people with rheumatic disease. Participants may be asked for permission to have some of their blood and urine samples stored and to obtain previously collected blood or tissue biopsy specimens that are no longer needed for clinical care, for research purposes. They may also be asked to give additional blood or urine samples. Participants will be followed every year for 5 years (either in person or by questionnaire) to evaluate any changes in their condition. The final 5-year evaluation will repeat some of the questionnaires and procedures described above.