title: Dihydrofolate reductase activity in primary brain tumors in children.
abstract: OBJECTIVE
  Dihydrofolate reductase is an enzyme involved in cell proliferation and differentiation processes. A cytochemical method was used to detect and quantitate this enzyme at the cellular level in brain tumors in children.
  
  
  METHODS
  Twenty-six children, aged 1-12 years, with primary brain tumors were studied, eight with medulloblastoma, 10 with glioma, and eight with ependymoma or other tumors. The cytochemical technique was applied on touch preparations performed in the operating room form biopsy specimens.
  
  
  RESULTS
  Enzyme activity was apparent as cytoplasmic granules sometimes overlying the nucleus of tumor cells.
  
  
  CONCLUSIONS
  Activity of dihydrofolate reductase in the children with medulloblastomas and high-grade gliomas was higher than that reported in leukemic blast cells. In the other brain tumors, low grade gliomas, and ependymomas, the enzyme activity was weaker.
authors.affiliation: First Department of Pediatrics, University of Athens, Greece.
authors.forename: F
authors.initials: F
authors.lastname: Tzortzatou-Stathopoulou
authors.forename: J P
authors.initials: JP
authors.lastname: Panagiotou
authors.forename: A
authors.initials: A
authors.lastname: Xaidara
authors.forename: K
authors.initials: K
authors.lastname: Karydis
authors.forename: G
authors.initials: G
authors.lastname: Sfakianos
authors.forename: B
authors.initials: B
authors.lastname: Evagellinos
mesh_terms: D001932:Brain Neoplasms / Q000201:enzymology*; D002648:Child; D002675:Child, Preschool; D004806:Ependymoma / Q000201:enzymology; D005910:Glioma / Q000201:enzymology; D006801:Humans; D007223:Infant; D015470:Leukemia, Myeloid, Acute / Q000201:enzymology; D008527:Medulloblastoma / Q000201:enzymology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000201:enzymology; D013762:Tetrahydrofolate Dehydrogenase / Q000378:metabolism*
chemical_list: D013762:Tetrahydrofolate Dehydrogenase