Search results for "Propidium"
showing 10 items of 73 documents
Contact sensitizers modulate mechanisms of receptor-mediated endocytosis but not fluid-phase endocytosis in murine epidermal Langerhans cells.
1995
In order to define the influence of contact allergens on the fluid-phase endocytosis (FPE) of soluble molecules of murine epidermal Langerhans cells (LC), we studied the internalization of FITC-labeled bovine serum albumin (FITC-BSA), TRITC-labeled dextrane (TRITC-DEX) as well as horseradish peroxidase by LC. A 3-parameter flow-cytometric technique was performed for quantification of internalized FITC-BSA in LC using quantum red-labeled reagents for detection of la-antigen expression by LC and propidium iodide for exclusion of dead cells from analysis. A temperature-dependent rapid accumulation of FITC-BSA was noticed in time-course studies reaching a plateau between 1 and 2 h of in vitro c…
Glycogen synthase kinase 3β links neuroprotection by 17β-estradiol to key Alzheimer processes
2004
Estrogen exerts many of its receptor-mediated neuroprotective functions through the activation of various intracellular signal transduction pathways including the mitogen activating protein kinase (MAPK), phospho inositol-3 kinase and protein kinase C pathways. Here we have used a hippocampal slice culture model of kainic acid-induced neurotoxic cell death to show that estrogen can protect against oxidative cell death. We have previously shown that MAPK and glycogen synthase kinase-3beta (GSK-3beta) are involved in the cell death/cell survival induced by kainic acid. In this model and other cellular and in vivo models we have shown that estrogen can also cause the phosphorylation and hence …
Recent developments in the use of viability dyes and quantitative PCR in the food microbiology field.
2013
The increase in foodborne outbreaks highlights the need for rapid, sensitive and specific methods for food safety monitoring, enabling specific detection and quantification of viable foodborne pathogens. Real-time PCR (qPCR) combined with the use of viability dyes, recently introduced, fulfils all these requirements. The strategy relies on the use of DNA-binding molecules such as propidium monoazide (PMA) or ethidium monoazide (EMA) as sample pretreatment previous to the qPCR. These molecules permeate only membrane-compromised cells and have successfully been applied for different types of foodborne pathogens, including bacteria and viruses. Moreover, those dyes have been explored to monito…
Flow cytometric assay for estimating fungicidal activity of Amphotericin B in human serum
1992
We describe a simple and rapid bioassay for estimating fungicidal activity of Amphotericin B in human serum using flow cytometry. The method exploits the fact that Candida albicans damaged by Amphotericin B show a decrease in size and take up propidium iodide to exhibit a red fluorescence after deoxycholate treatment. These phenomena display characteristic dose dependencies, and their assessment permits serum fungicidal activity to be broadly grouped into three categories: (1) subfungicidal; (2) fungicidal; and (3) strongly fungicidal. In normal human serum, these three categories correspond to Amphotericin B concentrations of 0 less than or equal to 0.5 micrograms/ml, 0.75-1.5 micrograms/m…
Evaluation of Zataria multiflora Boiss. essential oil activity against Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes by pr…
2013
Essential oils (EOs) have long been applied as flavoring agents in foods, and due to their content in antimicrobial compounds, they have potential as natural agents for food preservation. Recently, real-time PCR in combination with PMA has successfully been applied to discriminate between live Escherichia coli O157:H7 and dead bacteria killed by cumin, clove, oregano and cinnamon EOs. In this study, initial experiments were performed in order to elucidate the minimum bactericidal concentration of Zataria multiflora EOs on E. coli O157:H7, Salmonella enterica and Listeria monocytogenes. Thereafter PMA-qPCR was applied in order to selectively quantify life cells within a bacterial population …
1,2,4-Oxadiazole Topsentin Analogs with Antiproliferative Activity against Pancreatic Cancer Cells, Targeting GSK3β Kinase.
2021
A new series of topsentin analogs, in which the central imidazole ring of the natural lead was replaced by a 1,2,4- oxadiazole moiety, was efficiently synthesized. All derivatives were pre-screened for antiproliferative activity against the National Cancer Institute (NCI-60) cell lines panel. The five most potent compounds were further investigated in various pancreatic ductal adenocarcinoma (PDAC) cell lines, including SUIT-2, Capan-1, and Panc-1 cells, eliciting EC50 values in the micromolar and sub-micromolar range, associated with significant reduction of cell migration. These remarkable results might be explained by the effects of these new topsentin analogues on epithelial-to-mesenchy…
Comparative analysis of eight cytotoxicity assays evaluated within the ACuteTox Project.
2013
A comparative analysis of eight cytotoxicity assays [the 3T3 and normal human keratinocytes Neutral Red Uptake (NRU) assay, the primary rat hepatocytes, human HepG2 and 3T3 MU assay, and the human A.704, SH-SY5Y and HepG2 cells propidium iodide (PI) assay] included in several work packages of the EU Integrated Project ACuteTox, has been carried out. The aim was to evaluate whether cells originating from liver, kidney and brain provided different in vitro acute toxicity results, and the influence of primary liver cells versus cell lines originated from the same tissue. Spearman rank correlation analysis and Hierarchical Cluster Analysis were performed based on the IC50 (50% inhibitory concen…
Apoptotic activity of isoespintanol derivatives in human polymorphonuclear cells
2016
Background: Inflammation is a complex physiopathologic response to different stimuli. Recently, some pharmacological strategies have been proposed that could be used for resolution of inflammation by enhancing apoptosis of inflammatory cells. Objectives: To study in vitro apoptotic activity of isoespintanol [ISO] and of two semi-synthetic derivatives, bromide isoespintanol [BrI] and demethylated isoespintanol [DMI], in human polymorphonuclear (PMN) cells. Methods: PMN were exposed to the different concentrations of ISO, BrI and DMI for 30 min in phosphate-buffered saline pH 7.4 containing 1 mg/mL glucose, 0.4 mM Mg2+, and 1.20 mM Ca2+. Viability was assessed by dimethylthiazol diphenyl tetr…
Potent membrane-permeabilizing and cytocidal action of Vibrio cholerae cytolysin on human intestinal cells
1997
Many strains of Vibrio cholerae non-O1 and O1 El Tor that cause diarrhea do not harbor genes for a known secretogenic toxin. However, these strains usually elaborate a pore-forming toxin, hitherto characterized as a hemolysin and here designated V. cholerae cytolysin, whose action on intestinal cells has not yet been described. We report that V. cholerae cytolysin binds as a monomer to Intestine 407 cells and then assembles into detergent-stable oligomers that probably represent tetra- or pentamers. Oligomer formation is accompanied by generation of small transmembrane pores that allow rapid flux of K+ but not influx of Ca2+ or propidium iodide. Pore formation is followed by irreversible AT…
Cytotoxic Action of Serratia marcescens Hemolysin on Human Epithelial Cells
1999
ABSTRACT Incubation of human epithelial cells with nanomolar concentrations of chromatographically purified Serratia marcescens hemolysin (ShlA) caused irreversible vacuolation and subsequent lysis of the cells. Vacuolation differed from vacuole formation by Helicobacter pylori VacA. Sublytic doses of ShlA led to a reversible depletion of intracellular ATP. Restoration to the initial ATP level was presumably due to the repair of the toxin damage and was inhibited by cycloheximide. Pores formed in epithelial cells and fibroblasts without disruption of the plasma membrane, and the pores appeared to be considerably smaller than those observed in artificial lipid membranes and in erythrocytes a…