Search Results
Results 201 - 250 of 1605
< 1 2 3 4 5 6 7 8 9 10 >
Tomankova Katerina - - 2009
We studied the morphology of the A549 cell line (human lung carcinoma cells) before and after photodynamic therapy (PDT) by atomic force microscopy. PDT was induced by an efficient light-emitting diode source with total light dose of 15 J cm(-2) in the presence of the sensitizer zinc-5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrine. In the presence ...
Mazure Nathalie M - - 2009
Normal and tumor cells subjected to a hypoxic microenvironment show evidence of autophagy. We hypothesize that cells will sense hypoxia as a warning signal to upcoming drastic microenvironmental conditions and that autophagy, acting as a survival mechanism, will provide time for cells to adapt. This work demonstrates for the first ...
Clarke Laura - - 2009
Neural stem cells (NSCs) can be derived from single mouse embryonic stem cells (ESCs) in the absence of instructive factors. Clonal primitive NSC (pNSC) colonies are formed first, and then give rise to clonal, fibroblast growth factor-dependent definitive neural stem cells (dNSCs). We tested low-oxygen culture as a potential method ...
Ferrer E - - 2009
The cytotoxic effects of mycotoxins, induction of reactive oxygen species (ROS) and generation of lipid peroxidation products in CHO-K1 cells were determined as function of increasing time of exposure and concentrations of beauvericin (BEA), patulin (PAT) and zearalenone (ZEA). The end points were evaluated after 24h of exposure, by the ...
Tomankova K - - 2009
High resolution imaging of biological structures and their changes induced by different agents such as drugs are commonly performed by confocal and electron microscopy. The past decade has witnessed an emersion of the atomic force microscopy (AFM) from solid-state physics into cell biology and even medical applications. For these reasons, ...
da Silva Marcelo Barbosa - - 2009
Paracoccidioides brasiliensis, a thermal dimorphic fungal pathogen, produces a melanin-like pigment in vitro and in vivo. We investigated the involvement of carbohydrates and monoclonal antibody to CD18, on phagocytosis inhibition, involving macrophage receptors and the resistance of melanized fungal cells to chemically generated nitric oxide (NO), reactive oxygen species (ROS), ...
Zhang Jun Jun - - 2009
To evaluate the influence of resveratrol on cellular zinc status, normal human prostate epithelial (NHPrE) cells were treated with resveratrol (0, 0.5, 1, 2.5, 5, and 10 microM) and zinc [0, 4, 16, and 32 microM, representing zinc-deficient (ZD), zinc-normal (ZN), zinc-adequate (ZA), and zinc-supplemented (ZS) conditions, respectively]. A progressive ...
S??rensen Brita Singers - - 2009
BACKGROUND: Solid malignant tumours are characterised by an inadequate vascular system, which can give rise to micro-regional hypoxic areas. As the negative impact of tumour hypoxia is believed largely to depend on dynamic changes in gene expression, it is important to identify the genes regulated by hypoxia to further enlighten ...
Wouters An - - 2009
Hypoxic tumour regions often contain viable cells that are more resistant to chemotherapy and/or radiotherapy, making it of key importance to analyse new combination treatments under both normoxic and hypoxic conditions. In this study, the impact of moderate hypoxia and anoxia on cellular characteristics was investigated in isogenic A549 cells ...
Haase Volker H - - 2009
Epithelial-to-mesenchymal transition (EMT) is a developmentally vital, molecularly complex cellular process by which epithelial cells lose apico-basal polarity and cell-cell contact, become motile, and acquire mesenchymal characteristics. Under pathophysiological conditions EMT has a central role in cancer progression and metastasis, and has been associated with fibrotic disorders. Microenvironmental changes such ...
Kishimoto Koshi N - - 2009
The influence of oxygen tension on the side population (SP) fraction sorted from ATDC5 chondroprogenitor cells was investigated. ATDC5 cells cultured in normoxia (20%) or hypoxia (1% oxygen) were compared. The SP fraction was significantly higher in the cells cultured in hypoxia. The gene expression of 3 ABC transporters, abcb1a/b ...
Ngô Charlotte - - 2009
Endometriosis is associated with chronic inflammation, and reactive oxygen species (ROS) are proinflammatory mediators that modulate cell proliferation. We have investigated whether the dysregulation of ROS production in endometriotic cells correlates with a pro-proliferative phenotype and can explain the spreading of this disease. Stromal and epithelial cells were purified from ...
Etzkorn James R - - 2009
We report a method for forming arrays of live single cells on a chip using polymer micro-traps made of SU8. We have studied the toxicity of the microfabricated structures and the associated environment for two cell lines. We also report a method for measuring the oxygen consumption rate of a ...
Kuhnert Verena M - - 2009
Individuals suffering from Fanconi Anemia (FA) exhibit a pronounced hypersensitivity to agents that cause DNA inter-strand crosslinks and frequently also to ionising radiation. However, fibroblast lines derived from FA patients generally show little or no radiosensitivity in vitro. Here, we sought to elucidate the role of the central FA protein ...
Sar Aylin - - 2009
Hypoxia is commonly found in human solid cancers and serves as a selective environment for the survival of aggressive cancer cells and as protection from anti-cancer therapies. In addition to a shift to anaerobic metabolism, the cellular response to hypoxia includes cessation of cell division and/or cell death. These mechanisms ...
Huang Yan - - 2009
AIMS: Glucocorticoids (GCs) are frequently used to treat various pulmonary diseases, which are typically accompanied by hypoxia. Whether hypoxia influences the effects of GCs on human airway cells remains unclear. The aim of the present study was to characterize changes in the expression levels of two isoforms of the glucocorticoid ...
Islam Mohammad Mahbub - - 2009
Thioglucoside glucohydrolase (myrosinase), TGG1, is a strikingly abundant protein in Arabidopsis guard cells. We investigated responses of tgg1-3, tgg2-1 and tgg1-3 tgg2-1 mutants to abscisic acid (ABA) and methyl jasmonate (MeJA) to clarify whether two myrosinases, TGG1 and TGG2, function during stomatal closure. ABA, MeJA and H(2)O(2) induced stomatal closure ...
Beckers Simone - - 2010
A dynamic respiration assay based on luminescence decay time detection of oxygen for high throughput toxicological assessment is presented. The method uses 24-well plates (OxoDishes) read with the help of a sensor dish reader placed in a humidified CO(2)-incubator. Adherent primary rat hepatocytes and the human hepatic cell line Hep ...
Lu Zhisong - - 2009
Quantum dots-induced cell growth inhibition effect and its photophysical mechanism were investigated in this report. Cell growth curve and atomic force microscopy show that QDs block cell division to inhibit the growth of bacterial cells. On the basis of combined biological and physical discoveries from cytochrome c reduction assay, hydrodynamic ...
van der Toorn Marco - - 2009
Reactive oxygen species (ROS) present in cigarette smoke (CS) are thought to contribute to the development of COPD. Although CS-ROS can hardly enter airway epithelial cells, and certainly not the circulation, systemic levels of ROS have been found to be elevated in COPD patients. We hypothesize that lipophilic components present ...
Sakdee Jaruma Beau - - 2009
INTRODUCTION: Postnatal human dental pulp is a potentially promising source of progenitor cells. Sustaining and amplifying progenitor cell populations would be beneficial for basic science research with application in pulpal regeneration. Hypoxia has been observed to promote the undifferentiated cell state in various stem cell populations. The purpose of this ...
Petit Emile - - 2009
Reactive oxygen species (ROS) have been suggested to participate in tumor emergence due to their mitogenic and apoptotic signaling, and as contributors to DNA structural damage. Here we report that progesterone and various synthetic steroids with progestin potencies (norethisterone acetate, MPA, and Tibolone) counteract cell growth induced by hydrogen peroxide ...
Kim Hyung-Ryong - - 2009
This study investigated the molecular mechanism by which Bax inhibitor 1 (BI1) abrogates the accumulation of reactive oxygen species (ROS) in the endoplasmic reticulum (ER). Electron uncoupling between NADPH-dependent cytochrome P450 reductase (NPR) and cytochrome P450 2E1 (P450 2E1) is a major source of ROS on the ER membrane. ER ...
Deng Xiaobing - - 2009
The kinase Mirk/dyrk1B mediated the clonogenic growth of pancreatic cancer cells in earlier studies. It is now shown that Mirk levels increased 7-fold in SU86.86 pancreatic cancer cells when over a third of the cells were accumulated in a quiescent G(0) state, defined by Hoechst/Pyronin Y staining. Depletion of Mirk ...
Groeger Gillian - - 2009
Reactive oxygen species (ROS) have traditionally been viewed as a toxic group of molecules; however, recent publications have shown that these molecules, including H(2)O(2), can also strongly promote cell survival. Even though the retina has a large capacity to produce ROS, little is known about its non-mitochondrial sources of these ...
Zhao Baozhong - - 2009
The water-soluble fullerene derivative gamma-cyclodextrin bicapped C(60) [(gamma-CyD)(2)/C(60), CDF0] has several clinical applications, including use as a drug carrier to bypass the blood ocular barriers or a photosensitizer to treat tumors in photodynamic therapy. We have assessed the potential ocular toxicity of (gamma-CyD)(2)/C(60) and its aggregated derivatives induced by UVA ...
Chung Woon-Gye WG Department of Chemistry, Oregon State University, Corvallis, OR 97331, United - - 2009
Proanthocyanidins (PCs) have been shown to suppress the growth of diverse human cancer cells and are considered as promising additions to the arsenal of chemopreventive phytochemicals. An oligomeric mixture of PCs from hops (Humulus lupulus) significantly decreased cell viability of human colon cancer HT-29 cells in a dose-dependent manner. Hop ...
Shao Junfei - - 2009
Resveratrol (Res) has been reported to elicit many cellular responses including cell cycle arrest, differentiation, and apoptosis. This makes it a novel and potential anticancer agent. Moreover, the lipophilicity of Res raises the possibility of its application as a potential model drug in nanoparticle based delivery systems. Resveratrol is incorporated ...
Wilhelm Jirí - - 2009
Reactive oxygen species (ROS) play several biological roles. We investigated the applicability of fluorescent probes for their detection (i) in rabbit lens epithelial cells during ageing in culture, and (ii) in thin sections of rat heart. We used dihydroethidium (DHE), dichlorofluorescin (DCFH), and dihydrorhodamine 123 (DHR) together with detection of ...
Acosta Miguel A - - 2009
We present the development and characterization of fluorescent oxygen-sensing microparticles designed for measuring oxygen concentration in microenvironments existing within standard cell culture and transparent three-dimensional (3D) cell scaffolds. The microparticle synthesis employs poly(dimethylsiloxane) to encapsulate silica gel particles bound with an oxygen-sensitive luminophore as well as a reference or normalization ...
Borgmann Sabine - - 2009
Reactive oxygen species (ROS) and reactive nitrogen species (RNS) play a crucial role in chemical signaling processes of biological cells. Electrochemistry is one of the rare methods able to directly detect these species. ROS and RNS can be monitored in the local microenvironment of cells in real time at the ...
Chan Elsa C - - 2009
The superoxide generating enzyme NADPH oxidase has received much attention as a major cause of oxidative stress underlying vascular disease. However, there is increasing evidence that oxidant signaling involving NADPH oxidase has other important roles in cell biology. Nox family proteins are the catalytic, electron-transporting subunits of the NADPH oxidase ...
Steinbrenner Holger - - 2009
Reactive oxygen species (ROS) are derived from cellular oxygen metabolism and from exogenous sources. An excess of ROS results in oxidative stress and may eventually cause cell death. ROS levels within cells and in extracellular body fluids are controlled by concerted action of enzymatic and non-enzymatic antioxidants. The essential trace ...
Verbelen P J - - 2009
The volumetric productivity of the beer fermentation process can be increased by using a higher pitching rate (i.e., higher inoculum size). However, the decreased yeast net growth observed in these high cell density fermentations can have a negative impact on the physiological stability throughout subsequent yeast generations. The use of ...
Sud Dhruv - - 2009
Calibration of fluorescent optical sensors for accurate, quantitative intracellular measurements in vivo suffers from lack of a representative medium that appropriately simulates the molecular complexity of the cytosol. We present a novel protocol for accurate intracellular oxygen sensing via fluorescence lifetime imaging microscopy (FLIM) using cell lysate-FLIM measurements to correct ...
Popa Radu - - 2009
Individual magnetosome-containing magnetic mineral particles (MMP) from magnetotactic bacteria grow rapidly such that only a small fraction (5%) of all magnetosomes contain dwarf (< or =20 nm) MMP. Studies of the developmental stages in the growth of MMP are difficult due to the absence of techniques to separate dwarf from ...
Wang XiaoBing - - 2009
This study is to test the sensitivities of different tumor cells to ultrasound irradiation at the frequency of 2.2 MHz for 60 s duration, and investigate the potential mechanism underlying different sensitivities. Three murine tumor models with distinct aggressiveness (S180, H-22 and EAC) were exposed to ultrasound to evaluate their ...
So Cheung-Wai - - 2010
Photodynamic therapy is a treatment that combines the use of three non-toxic components, viz. photosensitiser, light and oxygen to cause localised oxidative photodamage. In the present study, the antifungal effect of the photosensitiser, BAM-SiPc, an unsymmetrical bisamino phthalocyanine, was investigated. BAM-SiPc was effective in photo-inactivating Candida albicans in a dose-dependent ...
Robinson John M - - 2009
Phagocytic leukocytes, when appropriately stimulated, display a respiratory burst in which they consume oxygen and produce superoxide anions. Superoxide is produced by the phagocyte NADPH-oxidase system which is a multiprotein complex that is dissociated in quiescent cells and is assembled into the functional oxidase following stimulation of these cells. Also ...
Bedogni Barbara B Division of Radiation and Cancer Biology, Stanford University, Stanford, CA, - - 2009
The tissue microenvironment plays a critical role in cell survival and growth and can contribute to cell transformation and tumor development. Cellular interactions with the stroma and with other cells provide key signals that control cellular arrest or division, survival or death, and entrance or exit from a quiescent state. ...
Umekawa Tohru - - 2009
OBJECTIVE To test the hypothesis that exposure of a renal epithelial cell line, NRK52E, to calcium oxalate monohydrate crystals (COM) would up-regulate NADPH oxidase subunit p47(phox), enhance superoxide production and increase monocyte chemoattractant protein-1 (MCP-1) and osteopontin mRNA levels. MATERIALS AND METHODS Confluent cultures of NRK52E cells were exposed to ...
Zhang Rui R Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39216, - - 2009
Macula densa cells produce superoxide (O2-) during tubuloglomerular feedback primarily via NAD(P)H oxidase (NOX). The purpose of the present study was to determine NOXs expressed by the macula densa and the role of each one in NaCl-induced O2- production. To identify which isoforms are expressed, we applied single-cell RT-PCR to ...
Yoshii Hanako - - 2009
Oxygen is essential for life, and cells have therefore developed numerous adaptive responses to oxygen change. Here, we examined the difference in oxygen-control functions of human (HE), mouse (ME), and Syrian hamster embryo (SHE) cells cultured under different oxygen conditions (0.5%, 2% and 20%), and also examined whether oxygen tensions ...
Chou Duen-Suey - - 2009
In a previous study, we demonstrated that baicalein induces hydroxyl radical formation in human platelets but the mechanisms are unclear. Herein, we show, using an electron spin resonance technique, that baicalein also induces hydroxyl radical formation in B16F10 melanoma cells in a dose-dependent manner. Baicalein produced superoxide anions in the ...
Guo Shuhong - - 2009
Hypoxia inducible factor 1 (HIF-1) has been suggested to play a critical role in the fate of cells exposed to hypoxic stress. However, the mechanism of HIF-1-regulated cell survival is still not fully understood in ischemic conditions. Redox status is critical for decisions of cell survival, death and differentiation. We ...
Seo Kyo Seong - - 2009
The biochemical oxygen demand (BOD) determination was studied using a novel flow injection analysis (FIA) system with encapsulated Saccharomyces cerevisiae cells and an oxygen electrode and was compared with conventional 5-day BOD tests. S. cerevisiae cells were packed in a calcium alginate capsule at a dry cell weight of 250 ...
Deshpande Rahul Ravi - - 2009
We show the application of a novel optical on-line sensor fixed in spinner flasks for the online monitoring of dissolved O(2) concentrations during mammalian cell growth. Using this sensor that requires only minute changes to the flask to be made, we could determine the volumetric O(2) transfer coefficient as well ...
Chung Woon-Gye - - 2009
Proanthocyanidins (PCs) have been shown to suppress the growth of diverse human cancer cells and are considered as promising additions to the arsenal of chemopreventive phytochemicals. An oligomeric mixture of PCs from hops (Humulus lupulus) significantly decreased cell viability of human colon cancer HT-29 cells in a dose-dependent manner. Hop ...
Molter Timothy W - - 2009
Due to interest in cell population heterogeneity, the development of new technology and methodologies for studying single cells has dramatically increased in recent years. The ideal single cell measurement system would be high throughput for statistical relevance, would measure the most important cellular parameters, and minimize disruption of normal cell ...
Kuimova Marina K - - 2009
Singlet molecular oxygen, O(2)(a(1)Delta(g)), can be created in a single cell from ground-state oxygen, O(2)(X(3)Sigma(g)(-)), upon focused laser irradiation of an intracellular sensitizer. This cytotoxic species can subsequently be detected by its 1270 nm phosphorescence (a(1)Delta(g) --> X(3)Sigma(g)(-)) with subcellular spatial resolution. The singlet oxygen lifetime determines its diffusion distance ...
< 1 2 3 4 5 6 7 8 9 10 >