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Direct visualization of lipid aggregates in native human bile by light‐ and cryo‐transmission electron‐microscopy
Author(s) -
Kaplun Alon,
Talmon Yeshayahu,
Konikoff Fred M.,
Rubin Moshe,
Eitan Arie,
Tadmor Maria,
Lichtenberg Dov
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)80176-2
Subject(s) - transmission electron microscopy , gallbladder , vesicle , nucleation , electron microscope , microscopy , micelle , chemistry , crystallography , biophysics , materials science , biology , nanotechnology , membrane , biochemistry , aqueous solution , pathology , optics , medicine , organic chemistry , physics
The evolution of microstructures present in human gallbladder and hepatic bile was observed simultaneously by video‐enhanced light microscopy (VELM) and transmission electron microscopy of vitrified specimens (cryo‐TEM), as a function of time after withdrawal from patients. Fresh centrifuged gallbladder bile samples contained small (6 nm) spherical micelles in coexistence with vesicles (40 nm). Out of the seven bile samples investigated four contained, in addition, two types of elongated aggregates that have not been previously described. Uncentrifuged gallbladder bile also contained a mixture of ribbon‐ and plate‐like crystals seen by VELM, but not by cryo‐TEM. In aged (3–6‐week‐old) gallbladder bile samples VELM also revealed spiral and helical crystal structures. No such crystals were present in hepatic bile samples, although microcrystals, not observable by VELM were seen by cryo‐TEM in addition to micelles and vesicles. The similarity of these observations to those observed in bile models lends strong support for the validity of the model systems. Furthermore, the presence of microcrystals in hepatic bile samples, apparently devoid of crystals by light microscopy, indicates that under certain conditions the common criterion of ‘nueleation time’ (NT), based on light microscopy, does not represent the real time of nucleation. In the human bile samples investigated in this study the dissociation between NT and the time of observation of microcrystals was seen in hepatic but not in gallbladder bile samples. Hence, crystal growth may be rate limiting only in dilute biles.