| progressive multifocal leukoencephalopathy | <radiology> Demyelinating disease due to papovavirus, seen in immunosuppressed hosts: lymphoma, leukaemia, AIDS, TB, sarcoidosis, organ transplant, most prominent in pareito-occipital white matter, NO contrast enhancement (12 Dec 1998) |
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| disseminated necrotizing leukoencephalopathy | <radiology> DNL: demyelination due to radiation and chemotherapy, decreased density in deep white matter, with or without peripheral, patchy enhancement, calcification: basal ganglia, grey/white junction (12 Dec 1998) |
| leukoencephalopathy | White matter changes first described in children with leukaemia, associated with radiation and chemotherapy injury, often associated with methotrexate; pathologically characterised by diffuse reactive astrocytosis with multiple areas of necrotic foci without inflammation. Origin: Leuko-+ G. Enkephalos, brain, + pathos, suffering (05 Mar 2000) |
| leukoencephalopathy, progressive multifocal | Rare demyelinating disease of the central nervous system which develops in immunocompromised patients secondary to lymphoproliferative disease, immunosuppressive therapy, autoimmune disorders, or aids. It is caused by the jc virus, a polyomavirus. (12 Dec 1998) |
| metachromatic | Denoting cells or dyes that exhibit metachromasia. Synonym: metachromophil, metachromophile. (05 Mar 2000) |
| metachromatic bodies | Concentrated deposits consisting primarily of polymetaphosphate and occurring in many bacteria as well as in algae, fungi, and protozoa; m. Body's differ in staining properties from the surrounding protoplasm. See: metachromasia. (05 Mar 2000) |
| metachromatic granules | Granule's that stain a colour different from that of the dye used. See: metachromasia. Term sometimes used as a synonym for volutin. (05 Mar 2000) |
| metachromatic leukodystrophy | <radiology> Dysmyelinating disease, autosomal recessive, aryl sulfatase A -- absent from urine and serum, most present by 2 yrs, die at 3-4 yrs, may arise at any age, CT: decreased density of white matter, primarily in centrum semiovale, with or without focal gall bladder defects (!) (12 Dec 1998) |
| metachromatic stain | <technique> A stain, such as methylene blue, thionin, or azure A, that has the ability to produce different colours with various histological or cytological structures. (05 Mar 2000) |
| leukodystrophy, metachromatic | A sphingolipidosis where there is defective desulfation of galactosyl-3-sulfate ceramide due to a defective enzyme cerebroside sulfatase (arylsulfatase a). The result is an accumulation of sulfatide in neural and non-neural tissues which manifests as mental deterioration and severe disturbances of the central nervous system. (12 Dec 1998) |