1.New Strategy for Treatment-Resistant Solid Tumors in Children (Posted: 06/13/2006) - This clinical trial will assess the safety of of a drug called talabostat in combination with chemotherapy in pediatric patients with cancer who have not responded to or gotten worse after other treatments. 2.Chemotherapy for Recurrent or Treatment-Resistant Lymphomas (Posted: 07/26/2005) - In this trial, researchers are trying to determine whether a new drug called UCN-01 will help kill cancer cells in patients who have a type of lymphoma called anaplastic large cell lymphoma. 3.Treating Mouth Sores in Pediatric Chemotherapy Patients (Posted: 12/14/2004) - This trial is testing a homeopathic mouth rinse as a treatment for mucositis in young patients undergoing chemotherapy in preparation for stem cell transplantation. 4.Treatment to Slow Tumor Progression in Children with Neurofibromatosis Type 1 (Posted: 10/26/2004) - Researchers are testing the drug tipifarnib in children with neurofibromatosis type I to see if it will slow progression of plexiform neurofibromas.