Search results for "Culture media"
showing 10 items of 272 documents
Triiodothyronine-Induced Shortening of Chromatin Repeat Length in Neurons Cultured in a Chemically Denned Medium
1987
Abstract: At the time of terminal differentiation, mammalian cortical neurons undergo a dramatic change in the structural organization of their chromatin: the nucleosomal repeat length shortens from ∼200 base pairs in fetuses to a value of 165 base pairs after birth. These events occur several days after the end of neuronal proliferation. Previously, we reported that rat cortical neurons cultured in a very selective synthetic medium were not yet programmed to these events at the end of mitotic cycles. Herein, we report that addition of triiodothyronine to neuronal cultures induces a shortening of the chromatin repeat length comparable to the natural one. Copyright © 1987, Wiley Blackwell. A…
Selective culture of rat CNS neurons in a synthetic medium.
1983
A Chemically Defined Medium is described which facilitates the survival of neurons in primary cultures of rat cerebral hemispheres. More than 90% of all cells were identified as neurons using neurofilament as a marker in an immunocytochemical assay. In contrast, serum-supplemented medium, by stimulating nonneuronal cell proliferation, hinders the survival of neurons in culture.
Oligopeptide assimilation and transport by Oenococcus oeni
2008
International audience; Aims: Oenococcus oeni is a slow-growing wine bacterium with a low growth yield. It thrives better on complex nitrogen sources than on free amino-acid medium. We aimed to characterize the oligopeptide use of this micro-organism. Methods and Results: Several peptides of two to eight amino-acid residues were able to provide essential amino acids. The disappearance of various peptides from extracellular medium was assessed with whole cells. Initial rates of utilization varied with the peptide, and free amino acids were released into the medium. Conclusions: Oenococcus oeni was able to transport the oligopeptides with two to five amino-acid residues tested and to hydrolys…
Study of Spanish grape mycobiota and ochratoxin A production by Isolates of Aspergillus tubingensis and other members of Aspergillus section Nigri.
2005
ABSTRACT The native mycobiota of five grape varieties grown in Spain has been studied. Four (Bobal, Tempranillo, Garnacha, and Monastrell) were red varieties and one (Moscatel) was white. The main fungal genera isolated were Alternaria , Cladosporium , and Aspergillus . The isolation frequency of Aspergillus spp. section Nigri in contaminated samples was 82%. Ochratoxin A (OTA) production was assessed using yeast extract-sucrose broth supplemented with 5% bee pollen. Cultures of 205 isolates from this section showed that 74.2% of Aspergillus carbonarius and 14.3% of Aspergillus tubingensis isolates produced OTA at levels ranging from 1.2 to 3,530 ng/ml and from 46.4 to 111.5 ng/ml, respecti…
Predictive assessment of ochratoxin A accumulation in grape juice based-medium by Aspergillus carbonarius using neural networks
2009
Aims: To study the ability of multi-layer perceptron artificial neural networks (MLP-ANN) and radial-basis function networks (RBFNs) to predict ochratoxin A (OTA) concentration over time in grape-based cultures of Aspergillus carbonarius under different conditions of temperature, water activity (a(w)) and sub-inhibitory doses of the fungicide carbendazim. Methods and Results: A strain of A. carbonarius was cultured in a red grape juice-based medium. The input variables to the network were temperature (20-28 degrees C), a(w) (0 center dot 94-0 center dot 98), carbendazim level (0-450 ng ml(-1)) and time (3-15 days after the lag phase). The output of the ANNs was OTA level determined by liqui…
Amino acids requirements of measles virus in HeLa cells.
1973
A low plating efficiency for measles virus was obtained when arginine, threonine and isoleucine were omitted from Eagle's basal medium and a stimulatory effect on the plaque production was produced by increasing the concentration up to 0.5 mm of arginine and glutamine. However, of all amino acids in Eagle's basal medium, only methionine was found to be essential for the synthesis of infectious progeny virus. Omission of any one of the other amino acids from the culture medium permitted limited virus production, but none whatever could be detected in the absence of mediummethionine. Moreover, when methionine was restored to infected cultures after 24 hours of deprivation, release of virus be…
Fetal Calf Serum-Free Generation of Functionally Active Murine Dendritic Cells Suitable for In Vivo Therapeutic Approaches
2000
Standard protocols to generate mouse dendritic cells (DC) generally use culture medium supplemented with fetal calf serum; however, reinjection in vivo of DC cultured in fetal calf serum results in priming to xenogeneic proteins that clearly limits the use of such DC. We therefore established a fetal calf serum-free culture system for the generation of murine DC from bone marrow precursors. DC can be generated fetal calf serum-free using RPMI supplemented with 1.5% syngeneic mouse serum. Although the yield of DC grown under fetal calf serum-free conditions was somewhat lower than that of the standard culture, large numbers of DC could be generated without the exposure to xenogeneic proteins…
The impact of growth history and flagellation on the adhesion of variousListeria monocytogenesstrains to polystyrene
2009
International audience; The contribution of growth history and flagella to adhesion of Listeria monocytogenes was analysed. An in-frame deletion on the flagellin encoding gene (flaA) was performed in L. monocytogenes EGD-e to compare its adhesion ability with the parental strain, after cultivation at various pH values and temperatures. The pH, as well as the temperature, affected the adhesion of L. monocytogenes EGD-e. In addition, the adhesion of L. monocytogenes EGD-e was reduced in energy-depressed cells. Conversely, the physicochemical bacterial surface characteristics affected by growth history did not influence the adhesion. Adhesion variations observed among environmental and clinica…
Endothelial capillaries chemotactically attract tumour cells.
2001
Directional migration of capillaries towards tumour implants is generally assumed to be regulated by chemotaxis. Preliminary evidence has also been presented for the existence of a reverse chemotactic signalling pathway, with capillaries attracting tumour cells via paracrine factors. By using a variety of endothelial cell types and tumour cell lines, this study has systematically investigated chemotaxis between endothelial cells and tumour cells in two- and three-dimensional systems. Checkerboard analysis revealed faint attraction of human umbilical vein endothelial cells (HUVECs), but not porcine aortic endothelial cells (PAECs), by tumour cells. In reverse, both PAECs and HUVECs potently …
Subendothelial infiltration of neutrophil granulocytes and liberation of matrix-destabilizing enzymes in an experimental model of human neo-intima.
2008
SummaryIt was the objective of this study to examine the role of human neutrophil granulocytes (PMN) in an in-vitro model of human neo-intima developed for the study of atherosclerosis. Human granulocytes were subjected to a co-culture model of human endothelial and smooth muscle cells. Subendothelial lipid accumulation was achieved by addition of native LDL to the culture medium. Tissue samples were analyzed by immunohistochemistry and scanning/transmission electron microscopy, and culture supernatants were examined for the presence of interleukin- 8 (IL-8), MCP-1, GRO-α, elastase and matrixmetalloproteinase-8 (MMP-8). Following addition of 2 mg/ml LDL, adherence, transmigration and infilt…