Cerebral sponginess and GM3 gangliosidosis; ultrastructure and probable pathogenesis.

Extensive multifocal vacuolation of the cerebral hemispheres, brain stem, cerebellum, optic nerves and spinal cord were demonstrated in a 3 1/2 month-old infant. This co-existed with marked increases in cerebral and hepatic ganglioside GM3 (hematoside), absence of its higher homologues (GM1 and GM2) and absence of tissue N-acetylgalactosaminyl transferase. Ultrastructurally, there are major abnormalities in myelin and astroglia. The absence of identifiable "storage" material is believed to correlate with an enzymatic defect involved in ganglioside anabolism. A familial occurrence of this disorder is strongly suggested by the clinical history.

Unusual demyelinating disease. A form of diffuse-disseminated sclerosis.

A young man, in good health until the age of 22, developed progressive personality changes, lethargy, motor diffuculities, urinary bladder dysfunction, and convulsions. Spinal fluid abnormalities included monocytic pleocytosis and selective increase of gamma globulins. The clinical features and the structural lesions in the central nervous system are reminiscent of disseminated-diffuse sclerosis. Oligodendrocytes appeared normal in number and showed nonspecific abnormalities. Comparison of the structural lesions found in this case with those described in seven reports of demyelination indicates that the separation of this syndrome, as a distinct entity, may not be justified. We suggest that such cases be classified as myelinoclastic disorders, in the same category with multiple sclerosis and its variants.

Human Herpes simplex encephalitis (cellular events).

Electron microscopic demonstration of herpes viral particles in cerebral tissues obtained at autopsy was easily accomplished. Analysis of the structural abnormalities in this case offers support for the proposed mechanisms of cellular injury in herpes simplex encephalitis. Interference with synthesis of nucleic acids and glycoproteins which has been suggested by in vitro studies correlates well with the structural abnormalities of endoplasmic reticulum cisternae and changes in nuclear membranes, described in the case reported herein.

Histoplasma capsulatum in vessels of the choroid.

In a 3-year-old boy disseminated histoplasmosis was recognized from a liver biopsy. The patient died shortly afterwards and had foci of the disease in liver, spleen, and kidneys. Large numbers of yeast cells of Histoplasma capsulatum were found within histiocytes in other organs including the eye. This rare finding is remarkable in view of the search for Histoplasma capsulatum in the syndrome known as "so-called histoplasmosis of the choroid."