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The structural dimensions of capillary tight junctions and the uptake of 99mTc pertechnetate in human gliomas were studied. Quantitative analysis revealed a correlation between the uptake of radionuclides and the length of endothelial tight junctions. It is suggested that brain scintigraphy might be used for the selection of malignant brain tumors with altered tight junctions which might be accessible to chemotherapy with water-soluble agents.

Four cases of pituitary tumours, three chromophobe adenomas and one granular-cell-“myoblastoma”, showing abnormal vessels and tumour stain on carotid angiography are leported.The histological picture of the tumour showed features of active tumour growth. All three cases of chromophobe adenoma were malignant in the clinical sense.The possible significance of the angiographic findings is discussed.

Unusually large areas of remyelination occurred in demyelinated plaques within the spinal cord of a patient with longstanding multiple sclerosis (MS). The regenerated myelin was indistinguishable from that of the peripheral nerves by optical and electron microscopy. The myelinforming cells within the spinal cord, morphologically identical to the Schwann cells, could be traced to the spinal nerve roots. At the periphery of the remyelinated zones, astrocytic processes were present adjacent to the regenerated peripheral type myelinated fibers similar to those normally seen in the nerve roots close to the spinal cord. In addition, Rosenthal fibers were frequently seen in such zones. There was no appreciable clinical improvement in this patient attributable to the remyelination. The mechanism of such focal remyelination in this otherwise typical case of MS remains obscure.