Intercellular heterogeneity of expression of the MGMT DNA repair gene in pediatric medulloblastoma.

DNA methylation and epigenetic inactivation of the O6-methylguanine methyltransferase (MGMT) gene induces MGMT deficiency, reducing the tumor cell's DNA repair capacity and increasing its susceptibility to alkylating chemotherapeutic agents. Consequently, adult patients whose tumors are deficient in MGMT have better outcomes with alkylator chemotherapy, and MGMT methylation has been proposed as a screening marker of deficient tumors. In order to test the feasibility of this approach for medulloblastoma, a common brain tumor in children, we determined the methylation status, mRNA expression pattern, and protein expression of MGMT in a panel of clinical specimens.

Hypothalamic hamartoma secreting corticotropin-releasing hormone. Case report.

The authors describe a unique case of a 2-year-old boy with a hypothalamic hamartoma secreting corticotropin-releasing hormone (CRH). The patient presented with a history of behavioral disturbances progressing over 12 months. His neurological status was intact.

Detection of human herpesvirus-6 in mesial temporal lobe epilepsy surgical brain resections.

Background: Human herpesvirus-6 (HHV-6), a ubiquitous beta-herpesvirus, is the causative agent of roseola infantum and has been associated with a number of neurologic disorders including seizures, encephalitis/meningitis, and multiple sclerosis. Although the role of HHV-6 in human CNS disease remains to be fully defined, a number of studies have suggested that the CNS can be a site for persistent HHV-6 infection.

Objective: To characterize the extent and distribution of HHV-6 in human glial cells from surgical brain resections of patients with mesial temporal lobe epilepsy (MTLE).

Advances in the diagnosis, molecular genetics, and treatment of pediatric embryonal CNS tumors.

Embryonal central nervous system (CNS) tumors are the most common group of malignant brain tumors in children. The diagnosis and classification of tumors belonging to this family have been controversial; however, utilization of molecular genetics is helping to refine traditional histopathologic and clinical classification schemes. Currently, this group of tumors includes medulloblastomas, supratentorial primitive neuroectodermal tumors, atypical teratoid/rhabdoid tumors, ependymoblastomas, and medulloepitheliomas.