Search results for "cytotoxicity."
showing 10 items of 830 documents
Lymphocytes from hepatic inflammatory infiltrate kill rat hepatocytes in primary culture
1990
In the last few years it has become possible in the liver to isolate lymphocytes from inflammatory infiltrates and to culture them in vitro. Most of the lymphocyte clones obtained are CD 8 + cytotoxic cells, but interactions between these lymphocytes and hepatocytes in primary culture have not been analysed previously. In this study, cloned human T lymphocytes from liver biopsies and from the peripheral blood of patients with chronic hepatitis B or primary biliary cirrhosis, after phenotypical and functional characterization into CD 8+ or CD 4+ cytotoxic lymphocytes, were activated in an antigen-independent fashion by adding either anti CD 3 or anti CD 2/R-3 monoclonal antibodies to the cel…
Synthesis, biological evaluation, and structure-activity relationship study of novel cytotoxic aza-caffeic acid derivatives.
2010
Abstract Three series of aza-caffeic acid derivatives with different linkers were designed and synthesized. Each of the synthesized derivatives was then used in cytotoxicity screening on either 8 or 12 human cancer cell lines. The structure–activity relationships on three structural regions A, B, and C are analyzed in detail, indicating that a nine bond linker B, containing a piperazine unit, is the most favorable linker leading to the generation of molecules with potent cytotoxicities. Compound ( E )-1-(4-(3,4-dichlorobenzyl)piperazin-1-yl)-3-(4-(4-ethoxybenzyloxy)-3,5-dimethoxyphenyl)prop-2-en-1-one ( 80 ) exhibited the most significant and selective cytotoxicity to KB, BEL7404, K562, and…
Self-adjuvanting synthetic antitumor vaccines from MUC1 glycopeptides conjugated to T-cell epitopes from tetanus toxoid.
2013
The T-helper epitope peptide P30 (green in the scheme) from tetanus toxoid was used as the immunostimulant in MUC1 glycopeptide antitumor vaccines and apparently also acts as a built-in adjuvant. P30-conjugated glycopeptide vaccines containing three glycans in the immunodominant motifs PDTRP and GSTAP induced much stronger immune responses and complement dependent cytotoxicity mediated killing of tumor cells when applied in plain PBS solution without complete Freund's adjuvant.
The use of three-dimensional oral mucosa cell cultures to assess the toxicity of soldered and welded wires
2007
The aim of the present study was to determine whether there is a difference in toxicity and loss of viability of three-dimensional (3D) reconstructed human oral epithelium (RHOE) cell cultures induced by point-welded (PW), laser-welded (LW), and silver-soldered (SiS) orthodontic wires. Three types of soldered stainless steel (SS) wires: PW, LW, and SiS were prepared ( n = 3) and subjected to multiple end-point analysis (MEA). Six pieces were cut from each wire. Each piece was placed on the triplicate cell cultures (RHOE model based on TR 146 cells). After 24 hours of topical exposure, the cell cultures were cut and stained with haematoxylin/eosin. Toxicity was assessed by evaluating the mor…
A human hepatocellular in vitro model to investigate steatosis
2006
The present study was designed to define an experimental model of hepatocellular steatosis with a fat overaccumulation profile in which the metabolic and cytotoxic/apoptotic effects could be separated. This was accomplished by defining the experimental conditions of lipid exposure that lead to significant intracellular fat accumulation in the absence of overt cytotoxicity, therefore allowing to differentiate between cytotoxic and apoptotic effects. Palmitic (C16:0) and oleic (Cl 8: 1) acids are the most abundant fatty acids (FFAs) in liver triglycerides in both normal subjects and patients with nonalcoholic fatty liver disease (NAFLD). Therefore, human hepatocytes and HepG2 cells were incub…
Effect of the methacrylate-based endodontic sealer Epiphany on rat peritoneal macrophages viability
2011
Objective: To evaluate the effect of the endodontic sealer Epiphany on rat peritoneal macrophages viability. Materials and methods: Peritoneal macrophages were obtained from Wistar rats and resuspended in RPMI- 1640 medium. Undiluted (crude extract) and diluted extracts to 10%, 1%, 0.1%, 0.01%, 0.001% and 0.0001% of Epiphany, AH 26 and AH Plus sealers on RPMI-1640 medium were tested for cytotoxicity to rat peritoneal macrophages using the trypan blue dye exclusion assay. Data were analyzed statistically by the Kruskal-Wallis and Mann-Whitney tests at 5% significance level. Results: Crude extract of Epiphany killed 51% of cells, but was less cytotoxic that crude extracts of AH Plus and AH 26…
Cytotoxic effects of two acid solutions and 2.5% sodium hypochlorite used in endodontic therapy
2010
Aim: To evaluate the cytotoxicity of 15% citric acid, 5% phosphoric acid and 2.5% NaOCl on cultured fibroblasts using MTT colorimetric assay. Methodology: Irrigating solutions of 5% phosphoric acid, 15% citric acid, and 2.5% NaOCl, diluted at 0.1% and 0.5%, were applied to cell cultures of 3T3L1 fibroblasts. The cell viability was determined by means of MTT colorimetric assay after a period of 1, 6 and 24 hours. Percentages of cell viability were analyzed using the Kruskal-Wallis test for global comparisons and the Mann-Whitney U-test for pairwise comparisons. Results: The percentage of cell viability diminished progressively over a 24 hour period in all solutions at both dilutions. At 0.1%…
Ultraviolet B Irradiation Modulates the Immune System of Fish (Rutilus rutilus, Cyprinidae) II: Blood
2007
The effects of a single dose of ultraviolet B (UVB) radiation (0.4 J/cm2) on immunological functions by blood leukocytes and on hematological parameters was studied in roach (Rutilus rutilus), a teleostean fish. The respiratory burst of phorbol 12-myristate 13-acetate stimulated whole blood phagocytes increased significantly after UVB irradiation but spontaneous cytotoxicity of blood leukocytes toward 51chromium-labeled K562 target cells was not markedly altered. Differential cell counting revealed that UVB exposure significantly increased the proportion of granulocytes and significantly decreased the proportion of lymphocytes in the peripheral blood, whereas hematocrit and the total number…
Synthetic multivalent glycopeptide-lipopeptide antitumor vaccines: impact of the cluster effect on the killing of tumor cells.
2014
Multivalent synthetic vaccines were obtained by solid-phase synthesis of tumor-associated MUC1 glycopeptide antigens and their coupling to a Pam3 Cys lipopeptide through click reactions. These vaccines elicited immune responses in mice without the use of any external adjuvant. The vaccine containing four copies of a MUC1 sialyl-TN antigen showed a significant cluster effect. It induced in mice prevailing IgG2a antibodies, which bind to MCF-7 breast tumor cells and initiate the killing of these tumor cells by activation of the complement-dependent cytotoxicity complex.
Cytotoxicity of natural products and derivatives toward MCF-7 cell monolayers and cancer stem-like mammospheres
2015
Abstract Although cancer stem-like cells (CSCs) are rare, they can enter a non-proliferative or dormant state and resist therapy. Furthermore, quiescent CSCs are responsible for metastases that can appear after curative surgical treatment of a primary tumor. Because of drug resistance of CSCs, the development of novel therapies is urgently required that specifically target CSCs. Purpose The aim of the present study was to investigate the potential of a panel of natural products and derivatives to inhibit CSC-enriched mammospheres of MCF-7 breast cancer cells. Methods CD44high/CD24low cells were identified by flow cytometry and maintained as mammospheres. As a control, we used two clinically…