As demonstrated by selective spinal cord arteriography, over 80% of spinal cord arteriovenous malformations (AVM's) occupy a predominantly extramedullary position. Current therapy frequently requires surgical stripping of the long dorsal intradural vessel(s) from the underlying spinal cord over many cord segments. The authors report six patients with a dural arteriovenous fistula fed by a cluster of abnormal epidural arteries. These vessels, which surrounded and were embedded into the dural covering of a thoracic nerve root, drained into a long sinuous intrathecal paramedullary vein(s). The angiographic and surgical appearance of the intradural component of these lesions was identical to that of lesions previously classified as Type I AVM's of the spinal cord. All patients had symptoms and signs of myelopathy. In five patients, surgery was limited to coagulation and excision of the extradural vessels and division of the intradural arterialized vein. Progressive improvement began within days following surgery. No residual abnormality was demonstrated by postoperative selective spinal cord arteriography, which was performed in all five patients. The findings support those of Kendall and Logue, that surgery restricted to elimination of the arteriovenous fistula at the intervertebral foramen is curative, and that more extensive surgery is unnecessary for this subgroup of AVM's of the spinal cord. These lesions comprise a sizable percent of all spinal AVM's. Resolution of myelopathy in these patients supports the hypothesis that venous hypertension causes chronic progressive myelopathy.

The proteins synthesized and released by human astrocytoma cells cultured with radiolabeled amino acids were analyzed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate and by trichloracetic acid precipitation. A select group of extracellular proteins was released from the astrocytomas. The most abundant extracellular proteins were at least 250,000 daltons. Five other major proteins (P 175, P 125, P 60, P 47, and P 40) were 175,000, 125,000, 60,000, 47,000, and 40,000 daltons, respectively. The complement of proteins retained by the cells was considerably more complex than those released. Clinical efforts to enhance the immunologic response directed against human astrocytomas must distinguish between extracellular and retained antigens. The pattern of proteins released by gliomas might be diagnostically useful if present in cerebrospinal fluid or serum.

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This report presents the results of a study using multiple techniques of the established human cell line, LM, which has been developed in culture medium from a patient with a right temporoparietal glioblastoma. This cell line has human subtetraploid karyotype and has several features of a transformed line in culture. These include continuous propagation for 10 years, ability to form tumor nodules when transplanted into immunologically suppressed hamsters, and pleomorphic appearance. Ultrastructurally, it is characterized by multiple nuclei, few actin cables, and numerous surface-membrane microvilli, as well as abundant 9- to 10-nm cytoplasmic filaments. By its immunological reactivity, the line can be shown to contain glial fibrillary acidic protein at low levels, consistent with its glial origin and continued nature. Dibutyryl cyclic adenosine monophosphate (db-cAMP) induces formation of long astrocytic-like processes as well. Its membrane electrical characteristics include a low resting membrane potential and short time constant. Used in a microtiter antiglioma antibody cytotoxicity assay, LM yields a positive reaction to antibodies in the sera of 80% of patients with astrocytomas and only 9% of normal blood-bank donors, suggesting that it shares common antigens with other astrocytic tumor lines. The varied characteristics of this glioblastoma-derived line emphasize the "multiforme" nature on the neoplasm and suggest that for characterization of any such line, multiple parameters are necessary to allow comparison with other long-term glioblastoma lines in the literature. The usefulness of the LM line in in vitro cell biological, immunological, chemotherapeutic, and radiobiological studies of gliomas makes such efforts very worthwhile.

In 25 patients with intracranial gliomas, the autologous humoral response was studied in vitro with the use of microcytotoxicity (MC) and immune adherence (IA) assays. Antibodies were detected to autologous cultures in 44% of the cases by MC and in 50% by IA. These positive responses occurred in statistically different groups of patients, which suggested that different functional types of antibody were involved. Direct testing and absorption experiments showed that antibody was not significantly directed against autologous fibroblasts. Autologous cytotoxic antibodies were detected by 67% of astrocytoma cases and in only 10% of patients harboring a glioblastoma, the most anaplastic tumor of the glioma series. By means of the IA assay, absorption experiments were performed with the use of adult and fetal brains and cultures of autologous and allogeneic gliomas and fibroblasts. In this serologic system, the types of antigenic expression of a human glioma could be categorized as follows: 1) highly restricted glioma antigen(s), 2) common glioma antigen(s), 3) neurectoderm-derived antigen(s), and 4) brain and fibroblast-associated oncofetal antigen(s). The common glioma antigen and oncofetal antigen appeared to be qualitatively different, and the glioma antigen was expressed in uncultured tumor tissue.