This study is being offerred to patients that have acute myelogenous leukemia (AML) which is a cancer of the blood and these patients are going to have a stem cell transplant. This study is looking to determine how accurate two different laboratory tests are at detecting residual, or small numbers of cancer cells in the body before and after stem cell transplant, as well as whether or not results of these two tests show how well a recipient might do after transplant.

This is an 8 week drug study for children 6 to 17.5 years of age who have been diagnosed with hypertension. The purpose is to test the safety, tolerability and effictiveness of the study medication, Aliskiren. The study has 3 phases:

Screening Phase: All subjects will "wash out" (be on a placebo and no hypertensive medication) for a period of 7 - 21 days, during which they will be closely monitored the the physicians and research study staff.

Phase 1: (4 weeks/28 days) After the wash out period, all subjects will given the study drug, Aliskiren, with dosing based on weight.

Phase 2: (4 weeks/days). Patients will be randomized to receive either placebo or continue the aliskiren treatment assigned during Phase 1.

Once subjects have completed the 8 week study, they will be eligible to enroll in a 52 week extension study which looks at the long term safety, efficacy and tolerability of the study drug.

Voiding cystourethrograms (VCUGs) are a radiology study used to evaluate the urinary tract for a variety of conditions in the child. This can be particularly stressful and anxiety-provoking to a child and his/her parent. This research study is designed to identify what particular factors cause the most stress and anxiety.

The goal of this study is to understand parents' experiences at the end of their child's clinical trial in order to ease the transition process from clinical trials to standard of care for children and their families.This study is open to parents or the legal guardian of a pediatric research patient with a chronic illness who has completed a clinical trial within a 12 month period. Participation includes one brief interview and completion of a short questionnaire.

There is no current standard treatment for recurrent/refractory
medulloblastoma/PNET. The combination of the drugs temozolomide and
irinotecan has been used to treat adults and children with other types of cancer.
The combination has also been used in previous studies to treat a small number
of children with recurrent or refractory medulloblastoma/PNET as well as other
recurrent tumors, with encouraging results. This study uses the results of these
earlier studies, and looks at how well giving temozolomide and irinotecan daily
for 5 days every 28 days works when given to children and young adults with
recurrent or refractory medulloblastoma/PNET.

To collect information about the patient's leukemia and to seek the optimal treatment for children with ALL based on the individual level of risk of the cancer coming back after treatment. The risk groups are defined as a result of recent research conducted by the Children’s Oncology Group (COG). We would like to learn if the use of an experimental intrathecal therapy (ITT), which has been given to many people with ALL and has been well tolerated, would be better at preventing relapse in the central nervous system and improve disease outcomes in children with High Risk ALL.

The purpose of this pilot study is to investigate alterations in neural activity among individuals with Tourettes Syndrome. This will be acheived with single-pulse transcranial magnetic stimulation (TMS) and magnetic resonance imaging (MRI). These techniques are non-invasive. TMS is a brain stimulation method that allows us to measure the speed of information processing between brain regions as well as between the brain and the muscles. Combine with MRI, these techniques allow us to create a dynamic image of brain activity which may help guide future treatments. It is important to note that this will be used for research purposes and is not diagnostic.

A large randomized trial is necessary to evaluate whether rituximab can add benefit to the current chemotherapy regimen. Two pilot studies in children provide preliminary evidence of safety and activity of rituximab in this disease setting that support such a study. A Berlin-Frankfurt-Münster group (BFM) study, which tested a single dose of rituximab administered prior to chemotherapy, has shown tumor responses. A COG pilot study tested the safety and tolerability of the combination of rituximab with LMB chemotherapy and showed no increased short term toxicity.

The goal of this study is to better understand single ventricle circulation after its final palliation, the Fontan procedure. Each specific aim of the project directly affects current knowledge and/or aids future research in this population. In regards to Aim1, a better understanding the impaired responses to stress in single ventricle circulation will help direct future research on ways to improve quality of life as well as help direct medical and surgical therapies in this population. In regards to Aim 2, the mechanism that leads to improved exercise capacity with PDE5 inhibition will be elucidated. These three aims all compliment the overall goal of understanding the mechanisms that lead to heart failure in this high risk population.

This is a placebo-controlled smoking cessation treatment study for adolescents ages 14-21. After assessment and inclusion into the study, participants will be randomized to receive a 12-week double blind course of varenicline or placebo. All participants will concurrently participate in a contingency management (CM) intervention, specifically designed to reinforce participant retention.