Oxidative Stress Activates Membrane Ion Channels in Human Biliary Epithelial Cancer Cells (Mz-Cha-1).

Oxidative stress is known to contribute to cell damage. In several cell types, one of the earliest effects of oxidative stress is a rapid and substantial decrease in cell volume, which in turn regulates a broad range of cell functions, including development of apoptosis. Since volume regulation is closely coupled to membrane ion permeability, activation of ion channels may play an important role in oxidative stress-related cell injury.

Bimodal frequency-modulated atomic force microscopy with small cantilevers.

Small cantilevers with ultra-high resonant frequencies (1-3 MHz) have paved the way for high-speed atomic force microscopy. However, their potential for multi-frequency atomic force microscopy is unexplored. Because small cantilevers have small spring constants but large resonant frequencies, they are well-suited for the characterisation of delicate specimens with high imaging rates.

Preparation and characterization of light-switchable polymer networks attached to solid substrates.

Surface-attached polymer networks that carry light-responsive nitrospiropyran groups in a hydrophilic PDMAA matrix were prepared on planar silicon and glass surfaces and were characterized with respect to their switching behavior under the influence of an external light trigger. Functional polymers bearing light-responsive units as well as photo-cross-linkable benzophenone groups were first synthesized using free radical copolymerization. The number of spiropyran groups in the copolymer was controlled by adjusting the concentration of the respective monomer in the copolymerization feed.

Oxidative stress reduces Na+/H+ exchange (NHE) activity in a biliary epithelial cancer cell line (Mz-Cha-1).

In cholangiocarcinogenesis, chronic inflammation and oxidative stress play a key role. The Na(+)/H(+) exchanger (NHE) forms a potential link between control of intra- and pericellular pH and tumor development. Therefore, the effects of oxidant stress were determined by the use of tert-butyl hydroperoxide (t-BOOH) on Na(+)/H(+) exchange in a biliary epithelial cancer cell line (Mz-Cha-1).