Human brain tumor--derived cell lines: growth rate reduced by human fibroblast interferon.

The biological response modifier human beta-interferon had pronounced antigrowth effects on various histologic types of human brain tumor cells but no effects on a nontransformed cell line, MRC-5. The cultures of brain tumor cells showed severe alterations indicative of cell injury and death after exposure to beta-interferon for 2 to 6 days. Similar results were obtained with cells freshly explanted from human brain tumors. The results indicate that it may be possible to use fresh, explanted tumor tissue to identify patients who might benefit from therapy with beta-interferon.

Sitting prone position for the posterior surgical approach to the spine and posterior fossa.

The sitting prone position is compared with the standard laminectomy prone position and the sitting up position for posterior fossa surgery. We measured central venous pressure and airway pressure with the patient in different positions to determine the comparative efficacy of the sitting prone position. On a linear average, the central venous pressure increased by 6.83 cm H2O and the airway pressure increased by 3.16 cm H2O when the patient was changed from the supine to the standard prone position under general anesthesia; with a change from the standard prone position to the sitting prone position, the central venous pressure decreased by 10.45 cm H2O and the airway pressure decreased by 3.66 cm H2O. However, comparing the sitting prone position for posterior fossa surgery with the sitting up position, there was no statistically significant difference in central venous or airway pressure.

Commissural myelotomy.

The effect of commissural myelotomy in 24 cases with intractable pain is described. The operative technique employed with the operating microscope or magnifying glasses and a special myelotome is outlined. The results suggest an outstanding advantage in patients with bilateral metastases from malignancies except intrapelvic metastases. Patients with lumbar arachnoiditis showed a total failure of pain relief after 2 to 5 years, in spite of good relief temporarily.

Growth of astrocytomas in the human tumor clonogenic assay and sensitivity to mismatched dsRNA and interferons.

Nine astrocytoma specimens were received from seven patients and processed for testing in the human tumor clonogenic assay (HTCA). Cells derived from these specimens were challenged with human natural alpha-interferon (alpha-IFN) and beta interferon (beta-IFN), recombinant beta interferon (beta ser-IFN), and mismatched double-stranded (ds) RNA (Ampligen). Six of the astrocytoma specimens formed adequate colonies for drug sensitivity testing (greater than or equal to 30 colonies/plate), and all were high-grade (III-IV) tumors. Sensitivity was defined as a greater than or equal to 50% decrease in tumor colony formation following drug exposure and was observed with alpha-IFN (2/4), beta-IFN (3/4), and mismatched dsRNA (4/5) exposure. No decrease in colony growth was observed after recombinant beta ser-IFN exposure, and in 2 of 3 cases, colony formation was stimulated. The sensitivity of 75 non-CNS solid tumors to mismatched dsRNA was compared to the high-grade astrocytomas in the HTCA. Of the 10 additional histologic tumor types studied, carcinoid and renal cell carcinomas exhibited the greatest sensitivity to mismatched dsRNA: 63% and 52%, respectively. However, in comparison, 80% of the high-grade astrocytomas were sensitive, demonstrating that these gliomas are among the most sensitive of human tumors to mismatched dsRNA in vitro. Clinical trials of interferons and mismatched dsRNA, coupled with in vitro sensitivity studies, should further define their therapeutic potential.

Functional stimulation of the spinal cord in multiple sclerosis.

The authors describe the effect of electrical stimulation of the spinal cord in multiple sclerosis. After considering the nature of multiple sclerosis, the authors describe the background, character, mode and method of delivering electrical fields to the spinal cord. The results of this form of treatment and the implications of these observations in terms of physiologic mechanisms are discussed.

Improvement of motor function in multiple sclerosis by use of protopam chloride.

PAM, a cholinesterase reactivator, was administered orally and parenterally to 37 patients with multiple sclerosis and a control group of 24 patients with other neurological diseases and pain syndromes. The effects of the administration of this compound in these patients with and without electrical stimulation of the spinal cord were studied. The clinical response to the drug follows a known time course and is dose related. Administration of large doses orally or intravenously aggravates existing neurological dysfunction. With a dose of 1,000 mg intravenously, a characteristic response is the temporary appearance of new ophthalmological abnormalities, followed by significant improvement in motor control and behavior, which gradually subsides. Parenteral administration is superior to oral. Tolerance to the drug is observed. The presence of electrical stimulation of the spinal cord complements the action of the drug. When electrical stimulation is withdrawn, the effect of the drug reproduces the effect of the electrical stimulation. It is suggested there is a defect in cholinesterase in multiple sclerosis patients, and its reactivation may have a significant relationship to signs and symptoms.

Inhibition of turbulence in inertial-confinement-fusion hot spots by viscous dissipation.

Achieving ignition in inertial confinement fusion (ICF) requires the formation of a high-temperature (>10 keV) central hot spot. Turbulence has been suggested as a mechanism for degrading the hot-spot conditions by altering transport properties, introducing colder, mixed material, or reducing the conversion of radially directed kinetic energy to hot-spot heating. We show, however, that the hot spot is very viscous, and the assumption of turbulent conditions in the hot spot is incorrect. This work presents the first high-resolution, three-dimensional simulations of National Ignition Facility (NIF) implosion experiments using detailed knowledge of implosion dynamics and instability seeds and including an accurate model of physical viscosity. We find that when viscous effects are neglected, the hot spot can exhibit a turbulent kinetic energy cascade. Viscous effects, however, are significant and strongly damp small-scale velocity structures, with a hot-spot Reynolds number in the range of only 10-100.