This report describes unique contrast enhancement of the white matter on T1-weighted magnetic resonance images of two patients with disseminated necrotizing leukoencephalopathy, which developed from ...acute lymphoblastic leukemia treated with high-dose methotrexate. In both patients, the enhancement was more pronounced near the base of the brain than at the vertex. Necropsy of the first case revealed loss of myelination and necrosis of the white matter. Possible mechanisms causing such a leukoencephalopathy are discussed.
Two patients had an illness characterized by a positive family history, juvenile onset, macular cherry-red spots, myoclonus, generalized convulsions, and cerebellar ataxia. Neither had dementia, ...gargoyle facies, bone or joint deformities, or visceromegaly. Vacuolated lymphocytes were not seen in the peripheral blood or bone marrow. Specimens from the rectum and vermiform appendix showed Sudan black B-, Sudan III-, and PAS-positive granules within the neurons of the myenteric plexus. On electron microscopic examination, lysosome-like bodies, membranous cytoplasmic bodies, pleomorphic lamellated bodies, dense bodies, and lipofuscin-like bodies in the neurons were seen, with a suggestion of morphological transitional forms among them. Sialoglycopeptides, especially sialic acid, were increased in the urine, but excretion of acid mucopolysaccharides was normal. Assays of lysosomal enzymes in leucocytes showed normal enzymatic activity. On the basis of the clinical, biochemical, and histological results, we suggest that these two cases and four similar cases reported in the literature be classified differently from the previously described lipidoses, although it is not known whether these cases represent a new entity or merely a clinical variant of juvenile lipidosis.
In order to evaluate the potential involvement of immediate early genes in ischemic tolerance, we examined Fos- and Jun-related protein immunoreactivity in gerbil brain. Two minutes of ...preconditioning ischemia or sham operation was followed by 3-min ischemia 3 days later. The animals were sacrificed after 4 h to 7 days of survival. Fos immunoreactivity was seen in dentate hilar neurons 4 h after 3-min ischemia regardless of preconditioning. Jun immunoreactivity increased in dentate granule cells 4 h after 3-min ischemia without preconditioning. Prominent Jun immunoreactivity was induced in astrocytes in the CA1 region of gerbils with ischemic tolerance. The result suggests that Jun may contribute to the ischemic tolerance by inducing changes in gene expression in astrocytes.
