Faculty Bibliography

In this study the positron emission tomographic (PET)-18F-2-deoxy-2-fluoro-D-glucose (FDG) technique was used to study both normal aging and senile dementia. The results derived from 15 young normal subjects (mean age, 26 +/- 5 years) and 22 elderly normal subjects (mean age, 66 +/- 7 years) failed to indicate significant metabolic changes associated with age. A group of 24 patients with senile dementia (mean age, 73 +/- 7 years) showed consistent diminutions in regional glucose use relative to the elderly normals. Across all brain regions the diminutions were 17%-24%. There were also significant correlations between the measures of glucose use and the measures of cognitive functioning. Discriminant function classification analysis results indicate that better than 80% classification accuracy can be achieved for individual PET measures. These data suggest a possible future diagnostic use of PET in senile dementia.

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