Lipid determinants of endocytosis and exocytosis in budding yeast.

Cells maintain physicochemical characteristics of membranes in order to allow for proper function of membrane-associated cellular processes, such as endocytosis and exocytosis. To investigate the interplay between membrane properties and biological processes, we applied lipid engineering approaches that allowed for systematic manipulation of fatty acid unsaturation and sterol biosynthesis, the main regulators of membrane fluidity. In combination with electrophysiological membrane capacitance measurements, we were able to study the dependence of the endo- and exocytic activity of Saccharomyces cerevisiae on membrane lipid composition in vivo.

Stromal corneal dystrophy (possible Schnyder's dystrophy) with peripheral corneal degeneration - diagnostic and therapeutic challenges.

to highlight the diagnostic and therapeutic challenges in a case with central and peripheral corneal lesions. We present the preoperative investigations: anterior segment optical coherence tomography and ultrasound biomicroscopy; The excised cornea has been examined histopathologically. Preoperative assessment showed that peripheral lesion was not ectatic; Histopathological examination points to a possible corneal degeneration, with posttraumatic or infectious etiology for the peripheral lesion and gives some reasons to sustain the diagnosis of Schnyder's dystrophy for the central lesion.

Vesicle fusion and fission in plants and yeast.

Measurements of the membrane capacitance on animal cells has provided an excellent technique for monitoring of exo- and endocytotic activity in intact living cells. Here we review recent data in which the same technique was applied to plant cells and cells of the budding yeast Saccharomyces cerevisiae. The data show that unitary exo- and endocytotic events can also be measured with the same technique after removing the cell wall from these cells.

High-resolution membrane capacitance measurements for studying endocytosis and exocytosis in yeast.

Fusion of exocytotic vesicles with the plasma membrane gives rise to an increase in membrane surface area, whereas the surface area is decreased when vesicles are internalized during endocytosis. Changes in membrane surface area, resulting from fusion and fission of membrane vesicles, can be followed by monitoring the corresponding proportional changes in membrane capacitance. Using the cell-attached configuration of the patch-clamp techniques we were able to resolve the elementary processes of endo- and exocytosis in yeast protoplasts at high temporal and spatial resolution.

[Intelligent phaco--always necessary?].

Purpose: To assess the need of /P system use in soft cataract

Methods: prospective study--40 eyes with soft cataract (+/++); surgery with Infinity system, Ozil handpiece; in 20 eyes we used low levels (max 70%) of torsional ultrasound power and IP system; in 20 eyes we used higher levels of torsional ultrasound power without IP system; we assessed: the CME value and the presence of cornela edema.

Results: In cases with tosional ultrasound only: average value of CME--2.4; maxim value of CME--4.