Meningitis linfomatosa como sitio de recaída en la enfermedad de Hodgkin / Limphomatous meningitis as recurrence site in Hodgkin's disease

Intracraneal manifestations of Hodgkin's Disease (HD) are extremely rare, with an estimated incidence rate of approximately 0.5%. They can be classified as: 1) treatment-related leucoencephalopathy, 2) central nervous system infections, 3) paraneoplasic syndromes and 4) intracraneal lymphomas, which could be sub-classified into intraparenchymal or intradural masses. We describe a case of a 40 year-old male with mixed cellularity type HD who developed neurological manifestations as relapsed disease. Magnetic resonance imaging suggested leptomeningeal metastases and atypical cells were found in cerebrospinal fluid. The patient died from progressive disease refractory to third line chemotherapy. There are less than 50 similar cases reported in the literature. We review the clinical features and differential diagnosis of leptomeningeal metastases in Hodgkin's disease.

Use of isotopically radiolabelled GM3 ganglioside to study metabolic alterations in Salla disease.

We report the preparation of radioactive GM3 ganglioside and its use in the study of sialic acid storage disorders. For the first time GM3 was isotopically radiolabeled in three positions of the molecule: at the sialic acid acetyl group, [3H-Neu5Ac]GM3, at the C1 of the fatty acid moiety, [14C-Stearoyl]GM3, and at C3 of sphingosine, [3H-Sph]GM3. The radioactive GM3 administered to cultured human fibroblasts from a patient suffering from Salla disease was taken up by the cells and metabolized. An analysis of the distribution of radioactivity within the ganglioside metabolic derivatives showed an accumulation of free sialic acid and ceramide in the pathological cells.

Relationship between the regulation of membrane enzyme activities by gangliosides and a possible ganglioside segregation in membrane microdomains.

Laser and neutron scattering experiments showed that in mixed micelles of ganglioside GM2 and GT1b, a membrane mimicking system, the segregation of gangliosides may occur spontaneously. Photolabeling experiments using nitrophenylazide containing ganglioside GM1 proved that gangliosides added to cells in culture enter the cell and bind to its membrane as components of microdomains, which specifically interact with a protein of about 30 kDa. This suggests that ganglioside segregation may be a natural phenomenon. Gangliosides when added to granule cells in culture led to increase in protein phosphorylation, the effect exerted being related to the amount of ganglioside molecules inserted stably into the cell lipid layer and an increase of 0.7% of the cell original ganglioside content promoted an increase of 57% in the incorporation of 32P into cell membrane proteins. From the above results a possible relationship between ganglioside segregation and involvement of ganglioside in enzyme activity control is suggested.