Search Results
Results 401 - 450 of 2016
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Limoli C L - - 2007
Hippocampal precursors retain the capacity to proliferate and differentiate throughout life, and their progeny, immature neurons, can undergo neurogenesis, a process believed to be important in maintaining the cognitive health of an organism. A variety of stresses including irradiation have been shown to deplete neural precursor cells, an effect that ...
Trog D - - 2007
OBJECTIVES: Human gliomas have a catastrophic prognosis with a median survival in the range of one year even after therapeutic treatment. Relatively high resistance towards apoptotic stimuli is the characteristic feature of malignant gliomas. Since cell cycle control has been shown to be the key mechanism controlling both apoptosis and ...
Sapin Anne - - 2006
OBJECT: Irradiated autologous tumor cells are commonly used as a source of antigens in antiglioma vaccinations to activate the immune system. As cell number is often a limiting factor in these cells' preparation, the aim of the present study was to find a means that can lower the amount of ...
Barkan Lenore - - 2006
Leaf expansion, comprising cell division and cell enlargement, is controlled by light quality and quantity. The role of UV-B irradiance on leaf cell enlargement has not been determined. We studied the effect of a wide range of UV-B irradiances on the cell-enlargement-driven expansion of Phaseolus vulgaris L., cv. Contender (bush ...
Takai Daisaku - - 2006
Roles of reactive oxygen species (ROS) in damage to mitochondrial DNA (mtDNA) following ultraviolet (UV)-irradiation were investigated in the human hepatoma cell line SK-HEP-1. We altered the intracellular status of ROS by the overexpression of manganese superoxide dismutase (MnSOD) and/or catalase. Using HPLC, we analyzed 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo), known as a ...
Kowalczuk C I - - 2006
PURPOSE: To examine the wavelength dependence of cellular responses in human melanocytes and human melanoma cells exposed to ultraviolet radiation (UVR). MATERIALS AND METHODS: Primary human melanocytes and G361 human melanoma cells were exposed to ultraviolet-C (UVC), ultraviolet-B (UVB), or ultraviolet-A (UVA) radiation. Dose-response relationships for clonal cell survival were ...
Callegari A John - - 2006
Eukaryotic cells irradiated with high doses of UV exhibit cell-cycle responses referred to as G(1)/S, intraS, and G(2)/M checkpoints. After a moderate UV dose that approximates sunlight exposure and is lethal to fission yeast checkpoint mutants, we found unexpectedly that these cell-cycle responses do not occur. Instead, cells at all ...
Sumaru Kimio - - 2007
In order to meet the diversifying demand for the cell manipulation in the rapid progress of cell engineering, we developed a novel technique to capture the living cells on a culture substrate by irradiating light in a multiple manner. In clear contrast to the conventional cell patterning using the previously ...
Bottone M G - - 2007
Rose Bengal acetate (RB-Ac) can be used as a fluorogenic substrate for photosensitization of cells both in vivo and in vitro: once inside the cells, RB-Ac is converted into photoactive rose Bengal (RB) molecules which redistribute dynamically in the cytoplasm and, upon irradiation by visible green light, can damage organelles ...
Ayano Satoru - - 2006
We quantitatively examined the possible damage to the growth and cell division ability of Escherichia coli caused by 1064-nm optical trapping. Using the synchronous behavior of two sister E. coli cells, the growth and interdivision times between those two cells, one of which was trapped by optical tweezers, the other ...
Chen Ming-liang - - 2006
To observe the photoprotective effect and possible mechanisms of resveratrol for ultraviolet A (UVA) irradiated HaCaT cells. HaCaT cells under UVA irradiation with 5J/cm(2) were interfered with 0.01 mmol/L and 0.1 mmol/L resveratrol. The testing objects were divided into a control and a UVA irradiation group, and then we detected ...
Yasuda Takako - - 2006
Medaka (Oryzias latipes) embryos at 25-26 and 28-30 stages were irradiated with a single acute dose of 10 Gy of X-ray, which is lower than the LD(50 )of the embryos. The effects on developing brains were examined under a stereomicroscope in living embryos until hatching. All the irradiated embryos survived; ...
Maxson Michelle E - - 2007
We present a new method to measure capsule size in the human fungal pathogen Cryptococcus neoformans that avoids the limitations and biases inherent in India ink measurements. The method is based on the use of gamma-radiation, which efficiently releases the capsule from the cell. By comparing the volume of irradiated ...
Kim Hooi-Sung - - 2006
A dye-sensitized solar cell was constructed using a porphyrin photosensitizer and, in place of the usual iodide redox system, a solution in aniline solvent containing lithium perchlorate electrolyte, camphorsulfonic acid, and poly(ethylene oxide) copolymer. Irradiation generated polyaniline within the cell, initially following a proposed photoelectropolymerization mechanism, and eventually operating as ...
Vantieghem Katleen K Laboratory for Experimental Medicine and Endocrinology (LEGENDO), Gasthuisberg, Katholieke Universiteit Leuven, Leuven, - - 2006
Epidermal keratinocytes are able to produce 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and induce vitamin D activity upon UVB irradiation. To find out whether this property is keratinocyte specific, we investigated this characteristic in two other cell types, namely intestinal CaCo-2 cells and the macrophage-like differentiated THP-1 cells. THP-1 macrophages and preconfluent CaCo-2 ...
Shao Chunlin - - 2006
Bystander responses have been reported to be a major determinant of the response of cells to radiation exposure at low doses, including those of relevance to therapy. This study investigated the role of changes in calcium levels in bystander responses leading to chromosomal damage in nonirradiated T98G glioma cells and ...
Boutis Anastasios - - 2006
Gamma-irradiation leads to apoptosis and cell cycle arrest in eukaryotic cells. Olomoucine is a novel purine analog acting as a cyclin-dependent kinase inhibitor. The effects of olomoucine in gamma-irradiation mediated cell growth inhibition and apoptosis were studied in the Raji cell line (Burkitt's lymphoma). Gamma-irradiation caused a G2 arrest, increasing ...
Kato Takamitsu A - - 2006
We have investigated the use of the gamma-H2AX assay, reflecting the presence of DNA double-strand breaks, as a possible means for identifying individuals who are mildly hypersensitive to ionizing radiation, such as some ATM heterozygotes. We compared levels of gamma-H2AX foci after irradiation in cells from six apparently normal individuals ...
Godthelp Barbara C - - 2006
Fanconi anemia (FA) is an inherited cancer-susceptibility disorder, characterized by genomic instability and hypersensitivity to DNA cross-linking agents. The discovery of biallelic BRCA2 mutations in the FA-D1 complementation group allows for the first time to study the characteristics of primary BRCA2-deficient human cells. FANCD1/BRCA2-deficient fibroblasts appeared hypersensitive to mitomycin C ...
You Youngjae - - 2006
A core-modified porphyrin, 5-phenyl-10,15-bis(carboxylatomethoxyphenyl)-20-(2-thienyl)-21,23-dithiaporphyrin (IY69) was studied in vitro for photodynamic activity under a variety of experimental protocols. Variables included the cell line (the rodent mammary tumor cell line R3230AC or the human breast cancer cell line MCF-7), light fluence, time of exposure of the cell cultures to IY69, and ...
Jantová Sona - - 2006
The present study demonstrates photoinduced generation of superoxide anion radical and singlet oxygen upon UVA irradiation of berberine chloride, and its cytotoxic/phototoxic effects on murine fibroblast non-cancer NIH-3T3 and Ehrlich ascites carcinoma (EAC) cells. The EPR spectra monitored upon photoexcitation of aerated solutions of berberine evidenced the efficient activation of ...
Hayashi Tetsutaro - - 2006
The remarkable capability of planarian regeneration is mediated by a group of adult stem cells referred to as neoblasts. Although these cells possess many unique cytological characteristics (e.g. they are X-ray sensitive and contain chromatoid bodies), it has been difficult to isolate them after cell dissociation. This is one of ...
Ohnishi Ken - - 2006
PURPOSE: We examined the effects of a heat shock protein (hsp) inhibitor, N-formyl-3, 4-methylenedioxy-gamma-butyrolactam (KNK437), on the radiosensitivity of human glioblastoma cells (A-172). MATERIALS AND METHODS: Effects of KNK437 on radiosensitivity and cell cycle regulation were examined using colony formation assays, flow cytometry analysis and Western blot analysis. KNK437 was ...
Renno, ACM
Abstract Background and Objective: Some studies have shown that low-level laser therapy (LLLT) is able to stimulate the osteogenesis of bone tissue, increasing osteoblast proliferation and accelerating fracture consolidation. It is also suggested that LLLT may have a biostimulatory effect in tumor cells. However, the mechanism by which LLLT acts ...
Liu Quanhong - - 2006
The cytotoxic effect of PPIX on isolated sarcoma 180 cells induced by ultrasound was investigated. Tumor cells suspended in air-saturated PBS (pH 7.2) were exposed to ultrasound at 2.2 MHz for up to 60s in the presence and absence of protoporphyrin IX disodium salt (PPIX). The viability of cells was ...
Beneduci A - - 2007
In the present study we compared the proliferation behavior, the ultrastructural morphology and the glycolitic metabolism of K562 cells irradiated by low-power wide-band millimeter waves, with those of sham-exposed K562 cells (control), maintained in the same culture conditions. The gigaHertz radiation treatments, performed between 53-78 10(9) Hz, induced a noticeable ...
Bromley Regina - - 2006
In this study we have investigated a spatial distribution of cell growth after their irradiation using a modulated x-ray intensity pattern. An A549 human non-small cell lung cancer cell line was grown in a 6-well culture. Two of the wells were the unirradiated control wells, whilst another two wells were ...
Kimura Shinzo - - 2006
Ionizing radiation (IR) is the most enigmatic of genotoxic stress inducers in our environment that has been around from the eons of time. IR is generally considered harmful, and has been the subject of numerous studies, mostly looking at the DNA damaging effects in cells and the repair mechanisms therein. ...
Wang Rui-Juan RJ Institute of Radiation Medicine, Academy of Military Medical Sciences, Beijing 100850, - - 2006
To explore the effect of recombinant human interleukin-11 (rhIL-11) on the expressions of interleukin-11 receptor alpha-chain (IL-11Ralpha) and an additional signal transducer glycoprotein 130 (gp130) in intestinal epithelium cell line-6 (IEC-6) after neutron irradiation. Cultured IEC-6 cells were exposed to 4.0Gy neutron and treated with 100 ng/mL rhIL-11 12 h ...
Toussaint Martin - - 2006
The sensitivity of yeast Saccharomyces cerevisiae to DNA damaging agents is better represented when cells are grown in liquid media than on solid plates. However, systematic assessment of several strains that are grown in different conditions is a cumbersome undertaking. We report an assay to determine cell growth based on ...
Liu Feng - - 2006
BACKGROUND: Cockayne syndrome (CS) is a rare human genetic disorder characterized by increased UV sensitivity, developmental abnormalities and premature aging. Cells isolated from individuals with CS have a defect in transcription-coupled DNA repair. Despite the repair defect, there is no any increased risk of spontaneous or UV-induced cancer for CS ...
Berns, Michael W.
Single mitochondria of contracting myocardial cells were irradiated with an argon laser microbeam and the contractility changes of the cells were noted. Four series of irradiation experiments were conducted: (i) one cell of a two-cell group was killed, (ii) one cell of a multicell group was killed, (iii) one cell ...
Singh Rakesh Kumar - - 2006
Nucleotide excision repair (NER) is the most versatile and universal pathway of DNA repair that is capable of repairing virtually any damages other than a double strand break (DSB). This pathway has been shown to be inducible in several systems. However, question of a threshold and the nature of the ...
Petrović Ivan - - 2006
PURPOSE: To measure the ability of protons and gamma-rays to effect cell viability and cell survival of human HTB140 melanoma cells. MATERIALS AND METHODS: Exponentially growing HTB140 cells were irradiated close to the Bragg peak maximum of the 62 MeV protons or with 60Co gamma-rays with single doses, ranging from ...
Medrado Alena P - - 2006
Little is known about the action of laser rays on normal adipose cells. The present study attempts to observe the behavior of fatty cells submitted to laser therapy. Dorsal fat pads of normal adult rats were submitted to low-level laser irradiation applied locally through intact skin, with four different dose ...
Kazuhiko AWAYA / Hajime ...
Young adult male albino rats were exposed to 600 r of total-body X-irratiation and the occurrence of plasma cells was studied on sections made from thymus, mesenteric lymph nodes and spleen. One to 30 days after irradiation, the marked increase in percentage of plasma cell has occurred, reaching its peak ...
Mortensen M W - - 2006
In this paper we present surface modification strategies of boron carbide nanoparticles, which allow for bioconjugation of the transacting transcriptional activator (TAT) peptide and fluorescent dyes. Coated nanoparticles can be translocated into murine EL4 thymoma cells and B16 F10 malignant melanoma cells in amounts as high as 0.3 wt. % ...
Masuda Kazuhiko - - 2006
The LEC rat is reported to exhibit hypersensitivity to X-irradiation, deficiency in DNA double-strand break repair, and radio-resistant DNA synthesis. This character of the LEC rat has been thought to be due to abnormal G1 arrest in cells after X-irradiation. In this report, we re-investigated the effect of X-irradiation on ...
Leatherbarrow Emma L EL DNA Damage Group, Radiation and Genome Stability Unit, Medical Research Council, Harwell, Oxfordshire, - - 2006
To investigate quantitatively the induction and rejoining of DNA double strand breaks (DSB) in V79-4 and xrs-5 Chinese hamster cells and HF19 human fibroblast cells, using the phosphorylation of the histone protein H2AX (gamma-H2AX) as an indicator of DSB, exposed to low doses of either low linear energy transfer (LET) ...
Ukai Akiko - - 2006
DNA polymerase theta (Poltheta) is a family A polymerase that contains an intrinsic helicase domain. To investigate the function of Poltheta in mammalian cells, we have inactivated its polymerase activity in CH12 mouse B lymphoma cells by targeted deletion of the polymerase core domain that contains the catalytic aspartic acid ...
Seotsanyana-Mokhosi Itumeleng - - 2006
The photodynamic activity of water soluble mixed sulfonated metallophthalocyanines complexes: GePcSmix, SnPcSmix and SiPcSmix on human oesophageal carcinoma (SNO) cells are reported, and compared with the activity of the unmetallated H2PcSmix and of the newly synthesized water soluble adjacently substituted binaphthalo phthalocyanine (complex 3). The alkaline phosphate (ALP) showed damage ...
Fuentes J L - - 2006
This work was aimed to evaluate genotoxicity and antigenotoxicity activity against gamma-rays of a tannin fraction obtained from barks of Pinus caribaea, as well as to elucidate the antigenotoxic mechanisms involved in radioprotection by using different approaches as pre-, co- and post-irradiation cell treatments with plant extract. The tannin fraction ...
Wees, Caroline Geertruida Christina ...
The heart is built for life-long uninterrupted function, supporting blood flow through the organism. During life, the organism as well as its organs will become challenged by exogenous and endogenous stresses that should be coped with. To be able to adapt to stresses such as altered loading conditions, changes in ...
Müller Werner E G - - 2006
Until now the bystander effect had only been described in vertebrates. In the present study the existence of this effect has been demonstrated for the phylogenetically oldest metazoan phylum, the Porifera. We used the demosponge Suberites domuncula for the experiments in the two-chamber-system. The lower dish contained irradiated "donor" cells ...
Chaudhry M Ahmad - - 2006
In cell populations exposed to ionizing radiation, the biological effects occur in a much larger proportion of cells than are estimated to be traversed by radiation. It has been suggested that irradiated cells are capable of providing signals to the neighboring unirradiated cells resulting in damage to these cells. This ...
Bowler Deborah A - - 2006
Communication between irradiated and unirradiated (bystander) cells can result in responses in unirradiated cells that are similar to responses in their irradiated counterparts. The purpose of the current experiment was to test the hypothesis that bystander responses will be similarly induced in primary murine stem cells under different cell culture ...
DeVeaux Linda C - - 2006
Radiation-induced bystander effects have been seen in mammalian cells from diverse origins. These effects can be transmitted through the medium to cells not present at the time of irradiation. We have developed an assay for detecting bystander effects in the unicellular eukaryote, the fission yeast Schizosaccharomyces pombe. This assay allows ...
Newman David J - - 2006
The bystander effect is a process whereby the medium in which cells are irradiated at very low levels is presumed to contain a "low molecular weight" entity that will induce cell death and/or genetic changes in fresh mammalian cells when they are incubated in the medium. Following discussions at a ...
Alvarez M Gabriela - - 2006
The photokilling activity of a porphyrin-C(60) (P-C(60)) dyad was evaluated on a Hep-2 human larynx-carcinoma cell line. This study represents the first evaluation of a dyad, with high capacity to form a photoinduced charge-separated state, to act as agent to inactivate cells by photodynamic therapy (PDT). Cell treatment was carried ...
Di Pietro C - - 2006
Due to their ballistic precision, apoptosis induction by protons could be a strategy to specifically eliminate neoplastic cells. To characterize the cellular and molecular effects of these hadrons, we performed dose-response and time-course experiments by exposing different cell lines (PC3, Ca301D, MCF7) to increasing doses of protons and examining them ...
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