Search results for "Cytotoxic"
showing 10 items of 1673 documents
MAP kinase p38 and its relation to T cell anergy and suppressor function of regulatory T cells
2008
Diverse regulatory T cell populations (Treg) are important for the control of self tolerance and immune homeostasis. These include naturally occurring CD4+CD25+ Treg (nTreg) and induced Treg (iTreg). Tolerogenic dendritic cells, modulated by IL-10, are able to convert peripheral T cells into iTreg. These are anergic and characterized by a G(1) cell cycle arrest, dependent on elevated levels of the cdk inhibitor p27(Kip1). Novel data revealed a distinct pattern of MAP kinase activation in iTreg different from clonal T cell anergy, with enhanced activation of the p38-MAPKAP-K2/3 pathway. p38 is involved in cell cycle control and its activity is a prerequisite for the induction and maintenance…
Large clostridial cytotoxins — a family of glycosyltransferases modifying small GTP-binding proteins
1996
Some Clostridium species produce AB x -type protein cytotoxins of high molecular weight. These toxins constitute the group of large clostridial cytotoxins (LCTs), which have homologous protein sequences, exert glycosyltransferase activity and modify GTP-binding proteins of the Ras-superfamily. These characteristics render the LCTs valuable tools for developmental and cell biologists.
The Mucus of Actinia equina (Anthozoa, Cnidaria): An Unexplored Resource for Potential Applicative Purposes
2015
The mucus produced by many marine organisms is a complex mixture of proteins and polysaccharides forming a weak watery gel. It is essential for vital processes including locomotion, navigation, structural support, heterotrophic feeding and defence against a multitude of environmental stresses, predators, parasites, and pathogens. In the present study we focused on mucus produced by a benthic cnidarian, the sea anemone Actinia equina (Linnaeus, 1758) for preventing burial by excess sedimentation and for protection. We investigated some of the physico-chemical properties of this matrix such as viscosity, osmolarity, electrical conductivity, protein, carbohydrate, and total lipid contents. Som…
Complex Electromagnetic Fields Reduce Candida albicans Planktonic Growth and Its Adhesion to Titanium Surfaces
2021
This study evaluates the effects of different programs of complex electromagnetic fields (C.M.F.s) on Candida albicans, in planktonic and sessile phase and on human gingival fibroblasts (HGF cells). In vitro cultures of C. albicans ATCC 10231 and HGF cells were exposed to different cycles of C.M.F.s defined as: oxidative stress, oxidative stress/antibacterial, antibacterial, antibacterial/oxidative stress. Colony forming units (CFUs), metabolic activity, cells viability (live/dead), cell morphology, filamentation analysis, and cytotoxicity assay were performed. The broth cultures, exposed to the different C.M.F.s, were grown on titanium discs for 48 h. The quantity comparisons of adhered C.…
Steroidal saponins from the aerial parts of Cordyline fruticosa L. var. strawberries.
2019
A new sulfated steroidal derivative (fruticogenin A: 1-sulfo-australigenin-3-sodium sulphate, 1) and three new steroidal saponins named fruticoside K (3-sulfo-spirostan-25(27)-ene-1β,3β-diol-1-O-[α-L-rhamnopyranosyl-(1 → 4)-β-D-fucopyranoside], 2), fruticoside L (3-sulfo-spirostan-25(27)-ene-1β,3β,6α-triol-1-O-[α-L-rhamnopyranosyl-(1 → 4)-β-D-fucopyranoside], 3) and fruticoside M (spirostan-25(27)-ene-1β,3α-diol-1-O-[α-L-rhamnopyranosyl-(1 → 2)-α-L-rhamnopyranoside], 4) were isolated from the aerial parts of Cordyline fruticosa L. var. strawberries. Their structures were established on the basis of 1D and 2D NMR data, mass spectrometry and chemical methods. Compounds 2 and 4 exhibited weak …
In vitro cytogenetic and genotoxic effects of curcumin on human peripheral blood lymphocytes
2012
International audience; Curcumin has shown a wide range of properties such as anti-inflammatory and anti-carcinogenic properties. Many of these effects, mainly the anti-carcinogenic effect, could be linked to its anti-oxidant effects. Nevertheless, some studies suggest that this natural compound possesses both pro- and anti-oxidative effects and that curcumin could be a genotoxic agent for some cell lines. We evaluated the genetic damage induced by curcumin to human lymphocytes exposed to increasing concentrations (0-50 μg/ml) of curcumin. Biomarkers such as chromosome aberrations (CAs) and sister chromatid exchange (SCE) were analyzed. In addition to the cytogenetic analysis, the effect of…
The effect of light curing units and modes on cytotoxicity of resin-core systems
2010
Objective: The aim of this study was to compare the cytotoxic effects of various resin-based core materials that were cured with three light curing units (LCUs) in different modes on L?929 mouse fibroblast cells over 24 h and 72 h periods. Study design: Eighty-four cylindrical discs (2 mm in thickness and 6 mm in diameter) of each material (Rebilda, Voco; Build-It FR, Pentron; Clearfil DC Core, Kuraray and Bis-core, Bisco) were cured by QTH LCU (soft-up and high-power modes), LED LCU (exponential and standard modes) and PAC LCU (normal and ramp-curing modes). Then the samples were aged for 24 and 72 hours in Dulbecco?s Modified Eagle Medium/Ham?s F12 (DMEM/F12). After each ageing interval, …
The cytotoxicity of resin composites cured with three light curing units at different curing distances.
2011
Objective: The purpose of this study was to compare the effect of light curing distance on the cytotoxicity of five resin composites cured with three high-power light curing units. Study design: Seven cylindrical discs of each material (Grandio ®, Voco; Filtek ? Z250, 3M ESPE; Clearfil ? AP-X, Kuraray Co. Ltd.; Aelite ? LS, Bisco Inc. and Simile ®, Pentron) were cured. For curing, soft-up mode of quartz-tungsten-halogen, exponential mode of light emitting diode for 20 s, and ramp-curing mode of plasma arc light curing units for 6 s were used. The curing tip distances were determined as 2 and 9 mm and controlled via the use of metal rings. After ageing the samples for 24 and 72 hours in Dulb…
A p16INK4a-insensitive CDK4 mutant targeted by cytolytic T lymphocytes in a human melanoma.
1995
A mutated cyclin-dependent kinase 4 (CDK4) was identified as a tumor-specific antigen recognized by HLA-A2. 1-restricted autologous cytolytic T lymphocytes (CTLs) in a human melanoma. The mutated CDK4 allele was present in autologous cultured melanoma cells and metastasis tissue, but not in the patient's lymphocytes. The mutation, an arginine-to-cysteine exchange at residue 24, was part of the CDK4 peptide recognized by CTLs and prevented binding of the CDK4 inhibitor p16INK4a, but not of p21 or of p27KIP1. The same mutation was found in one additional melanoma among 28 melanomas analyzed. These results suggest that mutation of CDK4 can create a tumor-specific antigen and can disrupt the ce…
Applications of stable V79-derived cell lines expressing rat cytochromes P4501A1, 1A2, and 2B1.
1992
1. Chinese hamster V79-derived cell lines, stably expressing cytochromes P4501A1, 1A2, and 2B1 activities, were constructed by genetic engineering in continuation of our work to establish a battery of V79 derived cell lines designed to study the metabolism of xenobiotics. 2. Cell lines XEM1 and XEM2, expressing cytochrome P4501A1, were capable of the O-dealkylation of 7-ethoxycoumarin and the hydroxylation of benzo[a]pyrene. 3. Cell lines XEMd.MZ and XEMd.NH, expressing P4501A2, were shown to hydroxylate 17 beta-estradiol and 2-aminofluorene. 4. Cell line SD1, expressing cytochrome P4502B1, was able to hydroxylate testosterone stereo- and regio-specifically at the 16 alpha and 16 beta posit…