A B S T R A C T Short-term effects of cholic acid ingestion on hepatic accumulation, fecal excretion, and blood levels of protoporphyrin were studied in vivo in griseofulvin-induced protoporphyric mice. Experimental mice that received feed with 2% griseofulvin and 0.5% cholic acid were compared with control mice that received feed with 2% griseofulvin for 4 wk. Five mice from each group were assessed each week for liver and blood porphyrin levels. Fecal protoporphyrin was compared weekly in the total pooled output of each population. Mean protoporphyrin levels were significantly lower for liver (P < 0.0001), erythrocytes (P < 0.05), and plasma (P < 0.05), and higher for feces (P < 0.001) for the mice that were fed cholic acid. Microscopic protoporphyrin deposits, inflammation, necrosis, and dysplasia were more severe in livers of control mice. A second experimental design compared four regimens in the feed given to all mice after 1-wk induction with 2% griseofulvin: (a) 0.5% cholic acid, (b) no adulterant, (c) 2% griseofulvin and 0.5% cholic acid, and (d) 2% griseofulvin. No difference in protoporphyrin removal from livers of mice in groups 1 and 2 was observed after 1 and 2 wk of these regimens. The apparent reduction in hepatic protoporphyrin content in mice of group 3 as compared with group 4 at weeks 2 and 3 was not significant at P < 0.05.These data suggest that in selected circumstances, Drs. Sklar and Goldsman participated in these studies during student research elective periods at Columbia University College of Physicians and Surgeons. Address all correspondence to Dr. Poh-Fitzpatrick.

Twenty-seven formalin-fixed, paraffin-embedded skin samples were examined to determine the usefulness of the loss of beta-2-microglobulin (B2m) in determining the malignancy of the epithelial cells of skin tumors. Our results confirm that there is loss of B2m from the cell surface in certain malignant lesions whereas the cells in the clearly benign lesions retain B2m on their cell membrane. Variable staining in the low-grade malignant and premalignant lesions renders B2m as an unreliable cell surface marker for differentiating borderline lesions.