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Results 451 - 500 of 1802
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Manti Lorenzo - - 2006
This review addresses the purported interplay between actual or simulated weightlessness and cellular response to ionizing radiation. Although weightlessness is known to alter several cellular functions and to affect signaling pathways implicated in cell proliferation, differentiation and death, its influence on cellular radiosensitivity has so far proven elusive. Renewed controversy ...
Sonnemann Jürgen - - 2006
Histone deacetylase inhibitors (HDIs) are a promising new class of antineoplastic agents with the ability to induce apoptosis and growth arrest of cancer cells. In addition, HDIs have been suggested to enhance the anticancer efficacy of other therapeutic regimens, such as ionizing radiation (IR) or chemotherapy. The objective of this ...
Seo Hang-Rhan - - 2006
Thermoresistant (TR) clone of radiation-induced fibrosarcoma (RIF) cells have been reported to show adaptive response to 1 cGy of low dose radiation, and hsp25 and inducible hsp70 are involved in this process. In the present study, to further elucidate the mechanism of how hsp25 and inducible hsp70 regulate the adaptive ...
Raaphorst G P - - 2006
Cell lines mutant in specific DNA repair pathways were used to determine if these pathways are involved in adaptive responses. For these studies, the effect of deficiencies in homologous recombination repair (HR) were studied in the parental AA8 and mutant (irs)ISF cell line pair and for deficiencies in the nonhomologous ...
Manti Lorenzo - - 2006
The polykaryon-forming unit (PFU) cell survival assay is based on the postirradiation flow cytometric analysis of the DNA content accumulated in high-ploidy cells (polykaryons) induced by the cytokinesis inhibitor cytochalasin B and can provide a meaningful measure of cell radiosensitivity. In this assay, cell survival is defined as the ability ...
Moon M S - - 2006
In previous studies, polyamine depletion by DFMO (alpha-difluoromethylornithine)-treatment reduced H(2)O(2)-induced apoptotic cell death by reduction of ferric ion uptake. In the present study, we analyzed the reduction of radiation-induced cell death by polyamine depletion. Exposure of HT29 cells to radiation induced severe cell death, but when cells were pretreated with ...
Kehlbach Rainer - - 2006
BACKGROUND AND PURPOSE: Due to its properties rhenium-188 (188Re) seems to be a promising radionuclide for stent coating to reduce restenosis following percutaneous transluminal angioplasty (PTA). In order to characterize the early effects of local 188Re treatment, human aortic smooth muscle cells (HaSMCs) were incubated with different doses of 188Re. ...
Belka C - - 2006
Radiotherapy remains a key component of modern multimodal anticancer treatment approaches. Although most clinically relevant improvements in radiation oncology are based on optimized radiation technology, it now becomes obvious that biology-based approaches will further boost the efficacy of modern radiation oncology. Of relevance to this is the question of the ...
Chang Hyo Won - - 2006
The Ku protein is essential for the repair of a majority of DNA double-strand breaks in mammalian cells. The purpose of this study was to investigate the relationship between the expression of Ku70/80 and sensitivity to radiation in cancer cell lines of the head and neck. The sensitivity to radiation ...
Yanagi Y - - 2006
To compare the theoretical retinal threshold time for endoilluminators and experimental phototoxic effect using A2e laden retinal pigment epithelial (RPE) cells. The spectral irradiances of three types of 20 gauge and 25 gauge endoilluminators, currently commercially available from two manufacturers, were evaluated in conditions where the total beam spectral power ...
Wright Eric G - - 2006
The dogma that genetic alterations are restricted to directly irradiated cells has been challenged by observations in which effects of ionizing radiation, characteristically associated with the consequences of energy deposition in the cell nucleus, arise in non-irradiated cells. These, so called, untargeted effects are demonstrated in cells that have received ...
Barcellos-Hoff Mary Helen - - 2006
Recent studies have highlighted crosstalk between irradiated cells and non-irradiated bystander cells and have uncovered high-frequency phenotypes of genomic instability in the progeny of irradiated cells that cannot be solely explained by radiation-induced mutation. It is difficult to explain these multicellular and multi-generational phenomena using the current paradigm of radiation ...
Little John B - - 2006
This report reviews briefly some of the findings reported over the past 2 years that enhance our understanding of the radiation-induced bystander effect. These developments include: technicological advances; the role of oxidative stress; the effect of cytoplasmic irradiation; cell-to-cell communication; and evidence that Connexin 43 mediated intercellular communication is induced ...
Heinrich Tilman - - 2006
Ataxia telangiectasia (AT) is an autosomal recessive multisystem disorder with increased radiosensitivity and cancer susceptibility. The responsible gene (ATM) consists of 66 exons and a coding region of 9171 bp which precludes direct sequencing as a screening assay for confirmation or exclusion of the clinical suspicion of AT. Peripheral blood ...
Caspersen,Eli Faksvåg
ABSTRACT Cervical cancer is one of the major causes of gynecological death worldwide. The degree of cancer progression of is categorized into different stages. Therapy is given depending on the stage of the cancer. Radiation is the main therapy in the advanced stages. Unfortunately, radiation therapy also causes severe damage ...
Prise Kevin M - - 2006
The use of microbeam approaches has been a major advance in probing the relevance of bystander and adaptive responses in cell and tissue models. Our own studies at the Gray Cancer Institute have used both a charged particle microbeam, producing protons and helium ions and a soft X-ray microprobe, delivering ...
Santini Maria Teresa - - 2006
High resolution proton nuclear magnetic resonance (1H-NMR) spectroscopy was used to examine the response of the MG-63 osteosarcoma cell line grown in monolayer and as 3-dimensional tumor spheroids to the same low dose (2 Gy) of ionizing radiation. The MG-63 cells and spheroids were irradiated at 24 h of growth ...
Miyamoto Akihiko - - 2006
The purpose of this study was to investigate radioadaptive response in 4 cell-lines under identical conditions using a colony assay. First, 4 cell-lines (V79, HeLa S3, EMT6 and SCCVII) were exposed to 8 Gy at various intervals after pretreatment with an adapting dose of 50 mGy or without it. Second, ...
Ballarini F - - 2006
In the last 10 years evidence has accumulated on the so-called radiation-induced 'non-targeted effects' and in particular on bystander effects, consisting of damage induction in non-irradiated cells most likely following the release of soluble factors by the irradiated ones. These phenomena were observed for different biological endpoints, both lethal and ...
Franken Nicolaas A P - - 2006
Clonogenic assay or colony formation assay is an in vitro cell survival assay based on the ability of a single cell to grow into a colony. The colony is defined to consist of at least 50 cells. The assay essentially tests every cell in the population for its ability to ...
Khaitan Divya - - 2006
BACKGROUND: Multicellular spheroids, an appropriate in vitro system for simulating 3-D tumor micro-milieu can be used for evaluating and predicting tumor response to therapeutic agents including metabolic inhibitors. However, detailed understanding of the nature, distribution and sensitivity/responses of cellular sub-populations to potential therapeutic agents/strategies is required for using this unique ...
Lau B M F - - 2006
The dose conversion coefficient (DCC) is used to assess the risk due to inhaled radon progeny in the human lung. The present work uses the microdosimetric approach and determines the linear energy transfer in the target cell nuclei. Killing of target cells was also taken into account through an effect-specific ...
Gerardi S - - 2006
At the low doses (and low dose rates) relevant to environmental and occupational radiation exposure (0-50 mSv), which are of practical concern for radiation protection, very few cells in the human organism experience more than one traversal by densely ionising particles in their lifetime, the intervals between the tracks, if ...
Journé Fabrice - - 2006
Both bisphosphonates and radiotherapy are highly effective for the management of bone metastases. Our in vitro study examined the cytotoxic effects resulting from combinations of ibandronate and ionising radiations (RX) in various sequences on breast cancer cells. Single radiation doses were given before, at halftime of, or after acute ibandronate ...
Tsutsumi Kaori - - 2006
Radiotherapy is an effective approach to treating many types of cancer. Recent progress in radiotherapy technology, such as intensity-modulated radiation therapy (IMRT) and three-dimensional (3D) radiotherapy, allow precise energy transfer to the tumor, which has improved local control rates. However, the emergence of tolerant cells during or after radiotherapy remains ...
Flatmark Kjersti - - 2006
The tumor response to preoperative radiotherapy of locally advanced rectal cancer varies greatly, warranting the use of experimental models to assay the efficacy of molecular targeting agents in rectal cancer radiosensitization. Histone deacetylase (HDAC) inhibitors, agents that cause hyperacetylation of histone proteins and thereby remodeling of chromatin structure, may override ...
Pyke E L EL MRC Radiation & Genome Instability Unit, Harwell, Oxfordshire OX11 0RD, UK. - - 2006
Ionising radiation can induce responses within non-exposed neighbouring (bystander) cells, which potentially have important implications on the estimates of risk at environmentally relevant doses. Using human skin fibroblasts (AG1522), a range of methods were used to investigate the nature of the signal(s) arising from the exposed cells. The signal(s) can ...
Kadhim M A MA Radiation and Genome Stability Unit, Medical Research Council, Harwell, Oxfordshire, UK. - - 2006
Genomic instability (GI) is a hallmark of tumorigenic progression and is observed as delayed genetic damage in the progeny of irradiated and unirradiated bystander cells. The expression of GI can be influenced by genotype, cell type and radiation quality. While several studies have demonstrated the induction of GI by high ...
Treizebré A A DHS Dpt., Lille Univ., - - 2006
Quite recently, it was found that metal wires can effectively guide terahertz radiation. We report in this communication an original planar excitation of surface wave on a single wire transmission line. This configuration is well suited for the design of THz BioMEMS dedicated to cell investigation. We show that we ...
Somodi Zsolt - - 2005
PURPOSE: To determine the role of single (SSB) and double strand break (DSB) repair in the induction and propagation of radiation-induced instability. MATERIALS AND METHODS: Two defined hamster cell lines with known DNA repair deficiencies in DSB repair (XR-C1) and base excision repair (EM-C11) and the parental wild-type line (CHO-9) ...
Liu Zhi-Zhong - - 2005
AIM: To investigate the prediction value of radiosensitivity of hepatocarcinoma cells for apoptosis and micronucleus assay. METHODS: Clonogenic assay, flow cytometry, and CB micronuclei assay were used to survey the cell survival rate, radiation-induced apoptosis and micronucleus frequency of hepatocarcinoma cell lines SMMC-7721, HL-7702, and HepG2 after being irradiated by ...
Kim S J - - 2006
PURPOSE: The antimalarial agent, artemisinin, also confers cancer-specific cytotoxic effects by reacting with ferrous iron atoms to form free radicals. Here, we investigated the radiosensitizing effects of dihydroartemisinin on glioma cells and assessed some possible mechanisms for these effects. MATERIALS AND METHODS: U373MG glioma cells treated with various concentrations of ...
Pauwels Bea - - 2005
Gemcitabine has excellent radiosensitizing properties, as shown in both preclinical and clinical studies. Radiosensitization correlated with the early S-phase block of gemcitabine. In the present study, we investigated the role of TP53 in the radiosensitizing effect of gemcitabine. Isogenic A549 cells differing in TP53 status were treated with gemcitabine during ...
Persaud Rudranath R Center for Radiological Research, Columbia University Medical Center, New York, New York 10032, - - 2005
A three-dimensional cell culture model composed of human-hamster hybrid (A(L)) and Chinese hamster ovary (CHO) cells in multicellular clusters was used to investigate low linear energy transfer (LET) radiation-induced bystander genotoxicity. CHO cells were mixed with A(L) cells in a 1:5 ratio and briefly centrifuged to produce a spheroid of ...
Zhu Aiping A Center for Radiological Research, Columbia University College of Physicians and Surgeons, New York, New York 10032, - - 2005
The cellular response to ionizing radiation is not limited to cells irradiated directly but can be demonstrated in neighboring "bystander" populations. The ability of mouse embryonic stem (ES) cells to express a bystander effect and the role of the radioresistance gene Rad9 were tested. Mouse ES cells differing in Rad9 ...
Clarke Shaun D - - 2005
Following a significant increase in the number of facilities in the world having and developing low- and high-linear energy transfer (LET) microbeams for experimental radiobiological studies, it is useful and demanding to establish reliable computational models to analyze such experiments. This paper summarizes initial MCNP5 calculations of the basic parameters ...
Shin You Keun - - 2005
To characterize the radiation-enhancing effects on human cancer cells and underlying mechanisms of celecoxib, a cyclooxygenase (COX)-2 selective inhibitor, and to ascertain whether its effects are COX-2 dependent. Clonogenic cytotoxicity assays and radiation survival assays after treatment with celecoxib +/- radiation were done on four human cancer cell lines that ...
Kawata Tetsuya - - 2005
Caffeine sensitizes cells to ionizing radiation, and this effect is believed to be associated with the disruption of DNA damage-responsive cell cycle checkpoints, which is controlled by ATM. Recent studies suggest that misrejoining of DSBs is one of the underlying mechanisms of AT cell hyper-radiosensitivity. In this study, we investigated ...
Chang P Y - - 2005
We have investigated molecular changes in cultured differentiating human lens epithelial cells exposed to high-energy accelerated iron-ion beams as well as to protons and X rays. In this paper, we present results on the effects of radiation on gene families that include or are related to DNA damage, cell cycle ...
Yashar Catheryn M - - 2005
Early stage cervical cancer is treated with surgery or radiation with equivalent results. Radiation is used for curative therapy of locally advanced disease and is combined with additional anti-tumor agents to improve control. We determined the potential role of genistein as a radiosensitizer for cervical cancer cells. Human cervical cell ...
Tanaka Tetsuji - - 2005
Death-associated protein kinase (DAPK) was originally identified as a positive mediator of interferon-gamma (IFNgamma)-induced apoptosis in cervical cancer cells, and interferons have been reported to enhance radiosensitivity in various types of squamous cell carcinoma. To examine whether DAPK can regulate cancer cell radiosensitivity, we investigated DAPK expression and radiosensitivity in ...
Le Gros Mark A - - 2005
X-ray tomography has been shown to provide insights into the internal structure of whole cells that can't be obtained by any other means. With recent advances in instrumentation and the advent of automated cryogenic sample stages, it has become possible to collect isotropic tomographic data from radiation-sensitive cells and to ...
Sutherland B M - - 2005
Travelers on space missions will be exposed to a complex radiation environment that includes protons and heavy charged particles. Since protons are present at much higher levels than are heavy ions, the most likely scenario for cellular radiation exposure will be proton exposure followed by a hit by a heavy ...
Lee Yi-Jang - - 2005
Cofilin is an actin-associated protein that belongs to the actin depolymerization factor/cofilin family and is important for regulation of actin dynamics. Cofilin can import actin monomers into the nucleus under certain stress conditions, however the biological effects of nuclear transport are unclear. In this study, we found that over-expression of ...
Belyakov Oleg V - - 2005
A central tenet in understanding the biological effects of ionizing radiation has been that the initially affected cells were directly damaged by the radiation. By contrast, evidence has emerged concerning "bystander" responses involving damage to nearby cells that were not themselves directly traversed by the radiation. These long-range effects are ...
Verschaeve L - - 2005
The possible effects of radiofrequency (RF) exposure on the genetic material of cells are considered very important since damage to the DNA of somatic cells can be linked to cancer development or cell death whereas damage to germ cells can lead to genetic damage in next and subsequent generations. This ...
Zhang Bo - - 2005
Peroxiredoxin I (Prx-I), a key member of the peroxiredoxin family, reduces peroxides and equivalents through the thioredoxin system. Our previous work has shown that expression of Prx-I in mammalian cells increases following ionizing radiation (IR), indicating that Prx-I actively responds to IR-induced reactive oxygen species (ROS) and suggesting that Prx-I ...
Wien F - - 2005
De-mountable calcium fluoride micro cells have been developed for use in synchrotron radiation circular dichroism (SRCD) spectroscopy. They have the advantages that they require only very small sample volumes (as low as 1 microliter) and have short path lengths (as small as 2 micrometers). Highly reproducible spectra can be obtained ...
Wright Eric G - - 2005
The mechanisms underlying the unequivocal association between ionizing radiation and the development of leukaemia remain unknown. Recent progress in defining sub-cellular events has contributed to our understanding of the production of genetic lesions in irradiated cells but the importance of tissue effects in response to radiation damage has attracted much ...
Cerù Maria Paola - - 2005
The aim of this work was to evaluate the effect of stratospheric radiations on neural tumour cells. ADF human glioblastoma cells were hosted on a stratospheric balloon within the 2002 biological experiment campaign of the Italian Space Agency. The flight at an average height of 37 km lasted about 24 ...
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