Faculty Bibliography

The polyamine metabolism of transplanted N-nitrosomethylurea-derived rat glioma was determined with radiolabeled putrescine used as a marker for malignancy. The uptake of putrescine in vivo was complete within 5 minutes and was specific for tumor tissue. The conversion of putrescine to spermine and other metabolites by the tumor was rapid, in contrast to the case for adjacent normal brain. These results suggest that putrescine labeled with carbon-11 may be used as a positron-emission tomographic tracer for the selective metabolic imaging of brain tumor and may be used in an appropriate model as a marker for tumor growth rate

To investigate hydroxocobalamin's role in preventing cyanide intoxication from sodium nitroprusside, we studied two groups of patients. One group received nitroprusside alone, and the other received nitroprusside and hydroxocobalamin. Red-cell and plasma cyanide levels were 83.44 +/- 23.12 and 3.51 +/- 1.01 microgram per 100 ml after nitroprusside alone and were 33.18 +/- 17.29 and 2.18 +/- 0.65 microgram per 100 ml after nitroprusside plus hydroxocobalamin. Acidosis developed in patients with red-cell cyanide levels higher than 75 microgram per 100 ml. When hydroxocobalamin infusion was stopped before sodium nitroprusside infusion was discontinued, blood cyanide levels and base deficit increased in a manner similar to that in the untreated group. The dose of nitroprusside used in each group did not differ statistically. These data show that hydroxocobalamin prevents cyanide transfer from red cells and plasma to tissue after nitroprusside metabolism, and thereby prevents cyanide toxicity from large intravenous doses of the drug