Faculty Bibliography

A patient in whom transesophageal echocardiography was performed to evaluate a possible source of cerebral embolization. The fact that the probe could not be passed easily beyond 35 cm from the incisors suggested esophageal obstruction or compression. A mass was seen posterior to the left atrium that was heterogenous and contained blood vessels, suggesting a malignancy. There were no complications of the procedure. Esophageal adenocarcinoma was confirmed on biopsy. Transesophageal echocardiography may be diagnostic of paracardiac mediastinal masses, both benign and malignant. Great care must be taken if passage of the probe through the esophagus is met with resistance, to avoid serious complications

Confluent cultures of Hep G2 cells were found to synthesize chenodeoxycholic and cholic acids continually. Chenodeoxycholic acid was synthesized at the rate of 58 +/- 8.6 micrograms/96 h, a rate more than 7-fold greater than that for cholic acid. Addition of 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha-triol but not the -3 alpha, 7 alpha-diol was followed by an increase in cholic acid synthesis, thus indicating a relatively low 12 alpha-hydroxylase activity. Endogenous synthesis of monohydroxy bile acid ester sulfates was found, with maximum rates of 135 and 74 micrograms/96 h for lithocholic and 3 alpha-hydroxy-5-cholenoic acids, respectively. Incubation of Hep G2 cells in medium containing 25% D2O permitted a comparison of the precursor/product relationship of cholesterol with 3 beta-hydroxy-5-cholenoic acid. The pattern of incorporation of deuterium was in accordance with that expected, thus allowing the conclusion that this monohydroxy bile acid is derived from cholesterol and should be considered together with chenodeoxycholic and cholic acids as a primary bile acid