1 September 1984

Elliot S. Vesell – 1 September 1984

Samuel W. French, Nancy C. Benson, Piera S. Sun – 1 September 1984 – Rats fed ethanol from 21 to 130 days were subjected to one or more episodes of hypoxia (6% O2) in order to determine if ethanol predisposed to centrilobular liver necrosis induced by hypoxia. Pair‐fed control rats were fed the diet regimen in parallel with the ethanol‐fed rats through an indwelling gastric cannula. The diet and ethanol were fed continuously 24 hr per day so as to maintain high blood alcohol levels in the ethanol‐fed rats.

J. Donald Ostrow – 1 September 1984 – Pigment gallstones are of two major types, black and earthy brown, each consisting of calcium salts of bilirubin and other anions, along with an unmeasured residue that is largely mucin glycoproteins. Studies in model systems indicate that the small proportion of unconjugated bilirubin in bile is solubilized by bile salts and that the ionized bilirubin is more soluble than the protonated diacid. Solubility is decreased by added lecithin but is unaffected by cholesterol.

R. Thomas Holzbach – 1 September 1984 – Major discrepancies exist between both the degree (or cholesterol excess limit) and duration of metastable cholesterol supersaturation in concentrated model biles and native human gallbladder bile. The comparatively reduced metastability of in vitro model systems suggests that a stabilizing factor is absent in these more concentrated systems. In contrast, the metastable supersaturation behavior of the dilute model and hepatic biles is similar particularly with respect to their markedly prolonged metastability, i.e., nucleation time.

Martin C. Carey – 1 September 1984 – Cholesterol is solubilized by bile salt and bile salt‐lecithin micelles without appreciable alteration in preexisting micellar size or structure. In dilute (∼ 3 gm per dl) model bile, but not in concentrated (∼ 10 gm per dl) systems, supramicellar concentrations of cholesterol are also solubilized in “stable” microdispersions of small lecithin‐cholesterol vesicles (∼ 200 to 400 A in radius).

Siegfried Lindenbaum, Natarajan Rajagopalan – 1 September 1984 – The kinetics of dissolution of dispersions of egg phosphatidylcholine (lecithin) by bile salts was studied by observing the decrease in turbidity as mixed micelles of lecithin and bile salts were formed. The rate of dissolution of lecithin corresponding to formation of mixed micelles was studied in the presence of dihydroxy bile salts, sodium deoxycholate, sodium chenodeoxycholate, sodium ursodeoxycholate and one trihydroxy bile salt, sodium cholate.

Stephen Barnes – 1 September 1984 – Studies of bile salt structure using nuclear magnetic resonance (NMR) and X‐ray crystallography have suggested that micellar association of bile salts is a function of side chain length and of packing of the side chain and the steroid nucleus. Lanthanide NMR probe analysis has been used to determine the structure of what is probably the monomer of the bile salt glycocholate.

Peter Schurtenberger, Norman A. Mazer, Werner Känzig – 1 September 1984 – Using quasielastic light scattering, we investigated the formation of vesicles produced spontaneously by diluting a mixed micellar solution of bile salt and lecithin beyond the micellar phase boundary. The vesicles were nearly monodisperse, and their size varied between 120 to 500 A depending upon the dilution conditions. A systematic study of the dependence of the vesicle size upon the bile salt and lecithin concentration was made and interpreted in terms of a simple equilibrium model.

Josip P. Kratohvil – 1 September 1984 – The current state of the knowledge of the size and the aggregation numbers of micelles formed in solutions of bile salts was evaluated. The experimental techniques considered include static light scattering, sedimentation equilibrium, membrane osmometry, sedimentation velocity and transla‐tional diffusion. The theoretical background of each method is briefly discussed, the working equations are summarized, and the limitations of each technique are enumerated.