Non-ohmicity and energy relaxation in diffusive 2D metals

We analyze current-voltage characteristics taken on Au-doped indium-oxide films. By fitting a scaling function to the data, we extract the electron-phonon scattering rate as function of temperature, which yields a quadratic dependence of the electron-phonon scattering rate on temperature from 1K down to 0.28K. The origin of this enhanced electron-phonon scattering rate is ascribed to the mechanism proposed by Sergeev and Mitin.Comment: 7 pages, 6 figure

The characterization of epithelial and stromal subsets of candidate stem/progenitor cells in the human adult prostate.

OBJECTIVES: Questions regarding the cell source and mechanisms in the initiation and progression of prostate cancer are today still open for debate. Indeed, our knowledge regarding prostate cell regulation, self-renewal, and cytodifferentiation is presently rather limited. In this study, we investigated these processes in the normal adult human prostate. METHODS: Dynamic expression patterns in prostate stem/progenitor cells, intermediate/transit-amplifying cells, and cell lineages were immunohistochemically identified in an in situ explant renewal model of the human normal/benign adult prostate (n=6). RESULTS: Cells with a basal phenotype proliferated significantly in explant cultures, whereas luminal cells went into apoptosis. Results further show down-regulation in tissue cultures of the basal and hypothetical stem cell marker Bcl-2 in the majority of cells, except in rare putative epithelial stem cells. Investigation of established (AC133) and novel candidate prostate stem/progenitor markers, including the cell surface receptor tyrosine kinase KIT and its ligand stem cell factor (SCF), showed that these rare epithelial cells are AC133(+)/CD133(low)/Bcl-2(high)/cytokeratin(+)/vimentin(-)/KIT(low)/SCF(low). In addition, we report on a stromal population that expresses the mesenchymal marker vimentin and that is AC133(-)/CD133(high)/Bcl-2(-)/cytokeratin(-)/KIT(high)/SCF(high). CONCLUSIONS: We provide evidence for epithelial renewal in response to tissue culture and for basal and epithelial stem/progenitor cell recruitment leading to an expansion of an intermediate luminal precursor phenotype. Data further suggest that SCF regulates prostate epithelial stem/progenitor cells in an autocrine manner and that all or a subset of the identified novel stromal phenotype represents prostate stromal progenitor cells or interstitial pacemaker cells or both

The characterization of epithelial and stromal subsets of candidate stem/progenitor cells in the human adult prostate

OBJECTIVES: Questions regarding the cell source and mechanisms in the initiation and progression of prostate cancer are today still open for debate. Indeed, our knowledge regarding prostate cell regulation, self-renewal, and cytodifferentiation is presently rather limited. In this study, we investigated these processes in the normal adult human prostate. METHODS: Dynamic expression patterns in prostate stem/progenitor cells, intermediate/transit-amplifying cells, and cell lineages were immunohistochemically identified in an in situ explant renewal model of the human normal/benign adult prostate (n=6). RESULTS: Cells with a basal phenotype proliferated significantly in explant cultures, whereas luminal cells went into apoptosis. Results further show down-regulation in tissue cultures of the basal and hypothetical stem cell marker Bcl-2 in the majority of cells, except in rare putative epithelial stem cells. Investigation of established (AC133) and novel candidate prostate stem/progenitor markers, including thecell surface receptor tyrosine kinase KIT and its ligand stem cell factor (SCF), showed that these rare epithelial cells are AC133(+)/CD133(low)/Bcl-2(high)/cytokeratin(+)/vimentin(-)/KIT(low)/SCF(low). In addition, we report on a stromal population that expresses the mesenchymal marker vimentin and that is AC133(-)/CD133(high)/Bcl-2(-)/cytokeratin(-)/KIT(high)/SCF(high). CONCLUSIONS: We provide evidence for epithelial renewal in response to tissue culture and for basal and epithelial stem/progenitor cell recruitment leading to an expansion of an intermediate luminal precursor phenotype. Data further suggest that SCF regulates prostate epithelial stem/progenitor cells in an autocrine manner and that all or a subset of the identified novel stromal phenotype represents prostate stromal progenitor cells or interstitial pacemaker cells or both

CysLT₂R signaling mediates anti-tumorigenic effects.

<p>(<b>A</b>) An alkaline phosphatase activity assay was used to determine the differentiation of Caco-2 cells. Cells were treated with IFN-α (500–2000 U/ml) and/or LTC₄ (40 nM) for 72 h. The alkaline phosphatase activity was determined by measuring the absorbance at 405 nm due to formation of <i>p</i>-nitrophenol. (<b>B</b>) QPCR quantification of mRNA expression of MUC2 with or without treatment with LTC₄ (40 nM), IFN-α (1000 U/ml), pretreatment for 30 min with CysLT₂R inhibitor AP-100984 (1 µM) or CysLT₁R inhibitor Montelukast (1 µM), in Caco-2 cells. (<b>C</b>) Caco-2 cells were incubated with LTC₄ (40 nM) and/or IFN-α (1000 U/ml) for 48 h in medium containing 1.5% serum. To determine proliferation by thymidine uptake, [methyl-³H] thymidine (0.5 µCi/well) was added to the wells during stimulation. (<b>D</b>) Cell migration was analyzed with Int 407 cells grown in the presence or absence of EGF (100 ng/ml) and/or LTC4 (40 nM). The cells were allowed to invade a collagen gel on top of a Boyden chamber for 18 hrs. The results are shown as means ± SD of at least three different experiments; *, P<0.05; **, P<0.01; ***, P<0.001.</p