Faculty Bibliography

An improved thin-layer chromatographic method is described for the facile separation of neutral oligosaccharides excreted in the urine of patients with mannosidosis. The urine sample is treated with mixed-bed ion-exchange resin to remove charged species. The eluate is then chromatographed on silica gel thin-layer plates with n-propanol water as the developer. Eleven unique orcinol-positive components can thus be resolved. The advantages of this method over previously described techniques are the ease and rapidity of assay, better resolution of components, and clarity of resolution. It should be applicable to other disease states in which distinctive neutral carbohydrate products are produced

Two novel branched-chain fatty acids, which appear to be unsaturated analogs of phytanic acid, have been observed in sera and urine of patients with Refsum's disease. They occur in both phospholipids and neutral lipids, and have been isolated and characterized

The effects of a low phenylalanine diet on six retarded phenylketonuric adults were assessed. An ABA individual-subject design was used in experiment I to assess the effects of a low phenylalanine diet on social and motor behavior. Following a baseline during which the subjects ingested a normal phenylalanine diet (phase A), a low phenylalanine diet (phase B) was administered in a double blind fashion. Finally, the baseline condition (phase A) was reinstated (normal diet). The low phenylalanine diet resulted in few significant behavioral changes for those subjects with which proper methodologic controls were employed. However, for two of six subjects motor behavior, including stereotypy and tremor, seem to have ameliorated. In experiment II, applied behavior analysis techniques, including differential reinforcement of other behavior and time out, were combined to radically reduce the frequency of stereotypy and self-abuse exhibited by one of the six subjects of experiment I

GM1-ganglioside hydrolysis by leukocytes and fibroblasts, tissues easily obtainable from patients, was investigated using 3H-labeled GM1 and was found to be at least as active as that reported for any other tissue. Sodium taurocholate was required for the reaction, the crude bile salt at an optimum concentration of 0.4% producing twice as much activity as pure taurocholate at its optimum concentration of 0.8%. Leukocyte GM1-ganglioside beta-galactosidase and 4-MU-beta-gal cleaving activities were similar, 134.5 +/- 23.3 and 179.8 +/- 25.4 nmol/h/mg protein, respectively. In cultured skin fibroblasts and amniotic fluid cells these enzyme activities were 4 to 5 times higher. Homozygotes for GM1-gangliosidosis showed negligible activity while in heterozygotes the leukocyte GM1-cleaving activity was reduced to one-third of control values. In leukocytes from patients with four other sphingolipid storage diseases the activity was either normal (Krabbe's, Tay-Sachs, Metachromatic leukodystrophy) or increased (adult Gaucher's)