= Salah Amasheh
{c}
<Salah Amasheh> studies the selective barrier formed by <epithelium>. A 2002 study led by Amasheh tested whether <claudin-2>, a <tight junction> <protein>, could change the passage of <ions> between neighboring <biological cells>. The investigators introduced <Complementary DNA> encoding <claudin-2> into a normally resistant cultured kidney <epithelium>, checked where the <protein> appeared, and compared electrical measurements with control cultures.<Claudin-2 expression induces cation-selective channels in tight junctions of epithelial cells by Salah Amasheh and others>[abstract, cell strains, transfection and localization]{ref}
<Claudin-2> expression increased conductivity through the spaces between <biological cells> by a factor of 5.6 and favored <cations> over <anions>. Transport of several larger test substances did not increase. The result illustrates a selective channel rather than an indiscriminate hole: greater passage of one class of <ions> need not mean greater passage of every dissolved substance. Combining localization, controls and measurements of different solutes made the interpretation stronger than an electrical measurement alone.<Claudin-2 expression induces cation-selective channels in tight junctions of epithelial cells by Salah Amasheh and others>[abstract, conductivity, ion selectivity and unchanged marker fluxes]{ref}
\Image[https://www.vetmed.fu-berlin.de/einrichtungen/zfg/we02/ma_bilder/amasheh_salah.jpg]
{title=Salah Amasheh}
{description=Portrait identified on https://www.vetmed.fu-berlin.de/einrichtungen/zfg/we02/mitarbeiter/interne/amasheh_salah/index.html[his institutional profile]; image credited there as private.}
{height=300}
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