I J Ophir

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I 2 Abstract Two methods are discussed to increase the dynamic range and enhance the signal-to-noise ratio in elastography (SNR,). One method uses variable applied strains to expand the elastographic dynamic range by selecting the strain estimates with the highest SNR, out of a multitude of strain estimates. The second one is a completely new estimator that(More)
The human colon adenocarcinoma cell line HT 29 grows in DMEM virtually without tight junctions (TJ). Fascia occludens type TJ can be induced in these cells by treatment with a variety of proteases or with hypertonic ammonium sulfate solution. The induced formation of TJ is not affected by pretreatment of the cells with cycloheximide or puromycin. The(More)
The human colon adenocarcinoma cell line HT29 displays an undifferentiated phenotype under standard growth conditions. When these cells were cultured for 21 days and then treated with forskolin, most of the cells formed brush borders on their apical surfaces. Brush border formation was inhibited by cytochalasin D but not by colchicine. Colchicine,(More)
Activation of the Ca2+/Mg2+ ATPase associated with highly purified Torpedo synaptic vesicles results in 45Ca2+ uptake. The accumulated 45Ca2+ is released by hypoosmotic buffer and by the Ca2+ ionophore A23187. Density-gradient centrifugation and permeation chromatography reveal that vesicular acetylcholine and the membrane-bound 45Ca2+ co-migrate, thus(More)
The non-polar human adenocarcinoma cells (HT29) when grown as monolayers or aggregates, have no tight junctions and no brush border. When these cells are treated with forskolin (15-100 microM) or cholera toxin (1 nM) intercellular lumina appear between the cells and about 30% of the cells facing the medium or the lumina are fully covered with a brush(More)
1. Addition of ATP to isolated highly purified Torpedo synaptic vesicles results in 45Ca2+ uptake. 2. Ca2+ dependent ACh release from Torpedo synaptosomes is accompanied by the phosphorylation of a specific protein with an apparent subunit molecular weight of about 100,000 (band alpha). 3. Activation of the presynaptic muscarinic receptors by an agonist(More)