Search results for "Culture media"
showing 10 items of 272 documents
Dystroglycan in Skin and Cutaneous Cells: β-Subunit Is Shed from the Cell Surface
2004
In skin, hemidesmosomal protein complexes attach the epidermis to the dermis and are critical for stable connection of the basal epithelial cell cytoskeleton with the basement membrane (BM). In muscle, a similar supramolecular aggregate, the dystrophin glycoprotein complex links the inside of muscle cells with the BM. A component of the muscle complex, dystroglycan (DG), also occurs in epithelia. In this study, we characterized the expression and biochemical properties of authentic and recombinant DG in human skin and cutaneous cells in vitro. We show that DG is present at the epidermal BM zone, and it is produced by both keratinocytes and fibroblasts in vitro. The biosynthetic precursor is…
Staphylococcal alpha-toxin kills human keratinocytes by permeabilizing the plasma membrane for monovalent ions
1993
Incubation of human keratinocytes with nanomolar concentrations of Staphylococcus aureus alpha-toxin leads to irreversible depletion of cellular ATP. The toxin forms hexamers in the target cell membranes, and rapid transmembrane flux of K+, Na+, and 86Rb+ is observed. Unexpectedly, pores formed in keratinocytes through application of low but lethal doses of alpha-toxin appeared to be considerably smaller than those formed in erythrocyte membranes. They permitted neither rapid influx of Ca2+ or propidium iodide, nor efflux of carboxyfluorescein. Larger pores allowing flux of all three markers did form when the toxin was applied at high concentrations. Flux of monovalent ions and reduction in…
Automated untargeted stable isotope assisted lipidomics of liver cells on high glucose shows alteration of sphingolipid kinetics
2020
Abstract Untargeted lipidomics is a powerful tool to discover new biomarkers and to understand the physiology and pathology of lipids. The use of stable isotopes as tracers to investigate the kinetics of lipids is another tool able to supply dynamic information on lipid synthesis and catabolism. Coupling the two methodology is then very appealing in the study of lipid metabolism. The main issue to face is to perform thousands of calculations in order to obtain kinetic parameters starting from the MS raw data. An automated computerized routine able to do accomplish such task is presented in this paper. We analyzed the lipid kinetics of palmitic acid (PA) in hepatoma liver cells cultured in v…
Dynamic laser speckle analyzed considering inhomogeneities in the biological sample
2017
Dynamic laser speckle phenomenon allows a contactless and nondestructive way to monitor biological changes that are quantified by second-order statistics applied in the images in time using a secondary matrix known as time history of the speckle pattern (THSP). To avoid being time consuming, the traditional way to build the THSP restricts the data to a line or column. Our hypothesis is that the spatial restriction of the information could compromise the results, particularly when undesirable and unexpected optical inhomogeneities occur, such as in cell culture media. It tested a spatial random approach to collect the points to form a THSP. Cells in a culture medium and in drying paint, repr…
Gram-positive bacteria on grass pollen exhibit adjuvant activity inducing inflammatory T cell responses.
2011
BACKGROUND: Recently, it has been established that pollen grains contain Th2-enhancing activities besides allergens. OBJECTIVE: The aim of this study was to analyse whether pollen carry additional adjuvant factors like microbes and what immunological effects they may exert. METHODS: Timothy pollen grains were collected and disseminated on agar plates, and the growing microorganisms were cultivated and defined. Furthermore, the immunologic effects of microbial products on DC and T cell responses were analysed. RESULTS: A complex mixture of bacteria and moulds was detected on grass pollen. Besides Gram-negative bacteria that are known to favour Th1-directed immune responses, moulds were ident…
Effect of Pro-inflammatory Stimuli on Tumor Cell-Mediated Induction of Endothelial Cell Adhesion Molecules in Vitro
2002
The object of our study was the question about the relevance of the tumor surrounding inflammatory cells with respect to the metastatic potential of the tumor cells. To imitate the role of inflammatory cells, three colon carcinoma (HT-29, HRT-18, and SW-620), one breast carcinoma (MCF-7), and one melanoma (ST-ML-12) cell lines were treated with pro-inflammatory stimuli, LPS, TNF-alpha, or IL-1beta. HUVEC monolayers were then stimulated by the collected supernatants (SN) of the tumor cells, following washing out of the applied stimuli. Analysis of CAM expression on HUVEC was performed using cell enzyme immunoassay. E-selectin, VCAM-1, and, in part, ICAM-1 were significantly up-regulated on H…
Effects of oxidoreduction potential combined with acetic acid, NaCl and temperature on the growth, acidification, and membrane properties of Lactobac…
2002
International audience; The effects of oxidoreduction potential (Eh) combined with acetic acid, NaCl and temperature on the growth, acidification, and membrane properties of Lactobacillus plantarum were studied. The culture medium was set at pH 5, and two different Eh values were adjusted using nitrogen (Eh = +350 mV) or hydrogen (Eh = -300 mV) gas. In reducing condition, the growth was slowed and the acidification delayed at 37 degrees C, but not at 10 degrees C. A synergistic inhibitory effect of reducing Eh, acetic acid and NaCl was observed, mainly for delaying the lag phase before acidification. These results may be explained by changes in ATPase activity, membrane fluidity and surface…
Combined action of redox potential and pH on heat resistance and growth recovery of sublethally heat-damaged Escherichia coli
2000
International audience; The combined effect of redox potential (RP) (from -200 to 500 mV) and pH (from 5.0 to 7.0) on the heat resistance and growth recovery after heat treatment of Escherichia coli was tested. The effect of RP on heat resistance was very different depending on the pH. At pH 6.0, there was no significant difference, whereas at pH 5.0 and 7.0 maximum resistance was found in oxidizing conditions while it fell in reducing ones. In sub-lethally heat-damaged cells, low reducing and acid conditions allowed growth ability to be rapidly regained, but a decrease in the redox potential and pH brought about a longer lag phase and a slower exponential growth rate, and even led to growt…
Screening of lactic acid bacteria for reducing power using a tetrazolium salt reduction method on milk agar.
2013
WOS:000315703100020 ; www.elsevier.com/locate/jbiosc; International audience; Reducing activity is a physiological property of lactic acid bacteria (LAB) of technological importance. We developed a solid medium with tetrazolium dyes enabling weakly and strongly reducing LAB to be discriminated. It was used to quantify populations in a mixed culture (spreading method) and screen strains (spot method).
Cloning and expression of genes involved in conidiation and surface properties of Penicillium camemberti grown in liquid and solid cultures.
2008
International audience; Based on bioinformatic data on model fungi, the rodA and wetA genes encoding, respectively, a RodA hydrophobin protein and the WetA protein involved in conidiation mechanisms, were PCR-cloned and characterized for the first time in Penicillium camemberti. These results, completed by a sequence of the brlA gene (available in GenBank), which encodes a major transcriptional regulator also involved in the conidiation mechanism, were used to compare, by qRT-PCR, the expression of the three genes in liquid and solid cultures in a synthetic medium. While expression of the brlA and wetA genes increased dramatically in both culture conditions after 4 days of growth, expressio…