Mount Sinai's Pediatric AIDS Clinical Trials Unit (ACTU) is applying for competitive renewal of its multi-hospital consortium to conduct clinical trials of new treatments for pediatric and perinatal HIV infection and the associated opportunistic infections and malignancies. Mount Sinai is been involved in the ACTG program since 1987 and has developed the capability to generate protocols, to recruit patients with HIV infection, coordinate data and specimen collection, perform virologic and immunologic evaluations, as well as pharmacokinetic studies, maintain quality control of laboratory results and data entry, and to collaborate with NIAID and the other institutions involved in adult and pediatric trials. The Adult and Pediatric units are integrated with each other and with clinical care. At each site the adult and pediatric units share space, administration and data management. The pediatric and Adult ACTUs serve as referral sources for each other and collaborate to provide a family-oriented program which increases accrual and retention. The immunology and virology laboratories process adult and pediatric specimens. Together the units have enrolled over 800 patients on more than 40 different protocols, and have consistently been among the leaders in enrollment of women, minorities, and intravenous drug users. The studies will be conducted at three hospitals (Mount Sinai Hospital, Beth Israel Medical Center and Elmhurst Hospital Center) which serve some of the highest AIDS incidence areas in the country and can offer access to trials to large numbers of HIV- infected women and children from groups which have been underrepresented in trials. The Pediatric ACTU will continue to participate in studies of perinatal transmission (where its investigators have been among the leaders), antiretroviral therapy and therapy of opportunistic infections. The unit plans to accrue and retain 30 to 35 new subjects per year.