Project description:Hypochlorous acid (HOCl) is a potent oxidant that is produced endogenously in mammalian tissue by phagocytes. Exogenous exposure to HOCl also can occur following inhalation of chlorine gas. HOCl has been implicated as a source of oxidative stress associated atherosclerosis and other diseases. The purpose of this study was to identify dose-dependent transitions in cellular response to hypochlorous acid (HOCl), with a focus on understanding how various cellular defense and stress dose-responses overlap.
Project description:Duplicate hybridizations with fluorochrome switching were performed following the first two fractions of total body irradiation for accumulated doses of 1.5 Gy and 3.0 Gy. Control samples for all hybridizations were from the same patient before the beginning of treatment. Keywords: dose response
Project description:Profiled the effect of oxidative stress on gene expression in the heads of adult Drosophila. The flies were fed sucrose with 15mM paraquat (experimental condition) or regular sucrose (control condition) for 30 hours, before harvesting at adult d3. Keywords = oxidative stress Keywords = paraquat Keywords: dose response
Project description:Transcriptional profiling of M. tuberculosis growing in log phase treated with various concentrations of carbon monoxide versus untreated controls Keywords: Dose response
Project description:Lymphocytes are the standard cell of a majority of biodosimetry approaches because of their availability and radiosensitivity. But progresses remain to be performed to bring down the minimum threshold of dose sensitivity. To find a lymphocyte subtype able to respond to low doses of ionizing radiation, we examined gene expression variations in different lymphocyte subpopulations using the microarray technology. Blood samples were independently exposed to 0, 0.05 and 0.5 Gray of ionizing radiations. Three and 24 hours after exposure, CD56+, CD4+ and CD8+ cells were negatively isolated. RNA from each condition was competitively hybridized on oligonucleotide microarrays. Keywords: Dose response, stress response, cell type comparison
Project description:ErbB receptor ligands, epidermal growth factor (EGF) and heregulin (HRG), induce dose-dependent transient and sustained intracellular signaling, proliferation and differentiation of MCF-7 breast cancer cells, respectively. In an effort to delineate the ligand-specific cell determination mechanism, we investigated time-course gene expressions induced by EGF and HRG that induce distinct cellular phenotypes in MCF-7 cells. To analyze the effects of ligand dosage and time for the gene expression independently, we developed a statistical method for decomposing the expression profiles into the two effects. Our results indicated that signal transduction pathways devotedly convey quantitative properties of the dose-dependent activation of ErbB receptor to early transcription. The results also implied that moderate changes in the expression levels of numbers of genes, not the predominant regulation of a few specific genes, might cooperatively work at the early stage of the transcription for determining the cell fate. However, the EGF- and HRG-induced distinct signal durations resulted in the ligand-oriented biphasic induction of proteins after 20 min. The selected gene list and HRG-induced prolonged signaling suggested that transcriptional feedback to the intracellular signaling results in a graded to biphasic response in the cell determination process, and that each ErbB receptor is inextricably responsible for the control of amplitude and duration of cellular biochemical reactions. Keywords: time course, dose response