Search results for "BLAST"
showing 10 items of 2136 documents
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…
Miltirone Induces G2/M Cell Cycle Arrest and Apoptosis in CCRF-CEM Acute Lymphoblastic Leukemia Cells
2015
Miltirone (1) is a diterpene quinone extracted from a well-known Chinese traditional herb (Salvia miltiorrhiza). We investigated the cytotoxic effects of miltirone toward sensitive and multidrug-resistant acute lymphoblastic leukemia cell lines. Miltirone inhibited multidrug-resistant P-glycoprotein (P-gp)-overexpressing CEM/ADR5000 cells better than drug-sensitive CCRF-CEM wild-type cells, a phenomenon termed collateral sensitivity. Flow cytometric analyses revealed that miltirone induced G2/M arrest and apoptosis. Furthermore, miltirone stimulated reactive oxygen species (ROS) generation and mitochondrial membrane potential (MMP) disruption, which in turn induced DNA damage and activation…
Low doses of paclitaxel potently induce apoptosis in human retinoblastoma Y79 cells by up-regulating E2F1.
2008
Paclitaxel (PTX) is an anticancer drug currently in phase II clinical trials. This study shows for the first time that low doses of PTX (5 nM) potently induce apoptosis in human retinoblastoma Y79 cells. The effect of PTX is accompanied by a potent induction of E2F1 which appears to play a critical role in the effects induced by PTX. PTX induced a dose- and time-dependent effect, with G2/M arrest, cyclines A, E and B1 accumulation and a marked modification in the status of Cdc2-cyclin B1 complex, the major player of the G2/M checkpoint. Apoptosis followed G2/M arrest. An early and prolonged increase in p53 expression with its stabilization by phosphorylation and acetylation and its nuclear …
Benzo[a]pyrene represses DNA repair through altered E2F1/E2F4 function marking an early event in DNA damage-induced cellular senescence
2020
AbstractTranscriptional regulation of DNA repair is of outmost importance for the restoration of DNA integrity upon genotoxic stress. Here we report that the potent environmental carcinogen benzo[a]pyrene (B[a]P) activates a cellular DNA damage response resulting in transcriptional repression of mismatch repair (MMR) genes (MSH2, MSH6, EXO1) and of RAD51, the central homologous recombination repair (HR) component, ultimately leading to downregulation of MMR and HR. B[a]P-induced gene repression is caused by abrogated E2F1 signalling. This occurs through proteasomal degradation of E2F1 in G2-arrested cells and downregulation of E2F1 mRNA expression in G1-arrested cells. Repression of E2F1-me…
Expression of the kinetochore protein Hec1 during the cell cycle in normal and cancer cells and its regulation by the pRb pathway.
2010
Highly Expressed in Cancer protein 1 (Hec1) is a subunit of the Ndc80 complex, a constituent of the mitotic kinetochore. HEC1 has been shown to be overexpressed in many cancers, suggesting that HEC1 upregulation is involved in the generation and/or maintenance of the tumour phenotype. However, the regulation of Hec1 expression in normal and tumour cells and the molecular alterations promoting accumulation of this protein in cancer cells are still unknown. Here we show that elevated Hec1 protein levels are characteristic of transformed cell lines of different origins and that kinetochore recruitment of this protein is also increased in cancer cell lines in comparison with normal human cells.…
Cyclophosphamide-Induced Morphological Changes in Dental Root Development of ICR Mice.
2015
Background Survivors of childhood cancer are at risk of late dental development. Cyclophosphamide is one of the most commonly used chemotherapeutic agents against cancer in children. The aim of this study was to investigate the effects of cyclophosphamide on root formation in the molars of growing mice and to assess the morphological changes in these roots using three-dimensional structural images. Methods We treated 16 12-day-old ICR mice with cyclophosphamide (100 mg/kg, i.p.) and 16 control mice with saline. At 16, 20, 24, and 27 days of age, the mandibular left first molars were scanned using soft micro-computed tomography. After scanning, the structural indices were calculated using a …
Glutathione is recruited into the nucleus in early phases of cell proliferation.
2007
We have studied the possible correlation between nuclear glutathione distribution and the progression of the cell cycle. The former was studied by confocal microscopy using 5-chloromethyl fluorescein diacetate and the latter by flow cytometry and protein expression of Id2 and p107. In proliferating cells, when 41% of them were in the S+G(2)/M phase of the cell cycle GSH was located mainly in the nucleus. When cells reached confluence (G(0)/G(1)) GSH was localized in the cytoplasm with a perinuclear distribution. The nucleus/cytoplasm fluorescence ratio for GSH reached a maximal mean value of 4.2 +/- 0.8 at 6 h after cell plating. A ratio higher than 2 was maintained during exponential cell …
Translocation of cdk2 to the nucleus during G1-phase in PDGF-stimulated human fibroblasts.
1997
We studied the subcellular distribution of cdk2 in synchronized, PDGF-stimulated human fibroblasts (FH109). After contact inhibition and serum depletion, more than 95% of FH109 cells were arrested in G0/G1-phase. PDGF-AB led to a 16-fold increase in proliferation compared with untreated cells. Cell cycle progression was studied by flow cytometric analysis, [3H]thymidine incorporation, and phosphorylation of the retinoblastoma gene product, pRB. Using Western blot analysis after subcellular fractionation, we revealed that after PDGF stimulation the phosphorylated (Thr 160), i.e., activated, form of cdk2 (33 kDa) first appeared in the nucleus at late G1-phase and persisted throughout until to…
Vinblastine-induced autophagocytosis in cultured fibroblasts
1991
1. Balb/c 3T3 fibroblasts were incubated in a medium containing 10(-5) M vinblastine for 1, 2 and 3 hr. Morphometric analyses were performed after an incubation period of 2 hr. 2. The volume fraction of advanced autophagic vacuoles increased tenfold (P less than 0.05) concomitantly with a sixfold decrease in round lysosomes (P less than 0.01). 3. The volume fractions of pleomorphic lysosomes, nascent autophagic vacuoles and residual bodies did not differ significantly from the control values. 4. In many cells, advanced autophagic vacuoles resembled multivesicular bodies, which may indicate that the type of autophagocytosis occurring in cultured fibroblasts is microautophagy.