Heat stress causes spatially-distinct membrane re-modelling in K562 leukemia cells

Cellular membranes respond rapidly to various environmental perturbations. Previously we showed that modulations in membrane fluidity achieved by heat stress (HS) resulted in pronounced membrane organization alterations which could be intimately linked to the expression and cellular distribution of heat shock proteins. Here we examine heat-induced membrane changes using several visualisation methods. With Laurdan two-photon microscopy we demonstrate that, in contrast to the enhanced formation of ordered domains in surface membranes, the molecular disorder is significantly elevated within the internal membranes of cells preexposed to mild HS. These results were compared with those obtained by anisotropy, fluorescence lifetime and electron paramagnetic resonance measurements. All probes detected membrane changes upon HS. However, the structurally different probes revealed substantially distinct alterations in membrane heterogeneity. These data call attention to the careful interpretation of results obtained with only a single label. Subtle changes in membrane microstructure in the decision-making of thermal cell killing could have potential application in cancer therapy

CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

EFFECT OF THE INTERNAL FIELD ON VIBRATIONAL BAND SHAPES AND INTENSITIES IN LIQUIDS

Author Institution: Department of Chemistry, Tufts UniversityAn analysis is given of the effect of the frequency dependence of the internal field upon band shapes and intensities in infrared and Raman spectra of liquids. It is shown that band shape in the Raman case is independent of the form of an isotropic internal field, and therefore a reflection of molecular interaction alone, whereas both effects are operative in generating infrared band shapes. Numerical calculations of infrared band shapes in liquids are presented for the Lorentz and Buckingham internal field functions. It is concluded that the interpretation of infrared band shapes in terms of molecular interaction must ordinarily be accompanied by an explicit analysis of the dependence of the band shape upon the frequency-dependent internal field