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Results 301 - 350 of 1609
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Platz, R.
In the present paper we present results on a-Si:H/a-Si:H stacked cells deposited in a single-chamber reactor by the very high frequency-glow discharge (VHF-GD) deposition technique at 70 MHz. Hydrogen dilution of the i-layer yields more stable amorphous p−i−n solar cells, similar to what is observed for RF deposition. High dilution ...
Olson Kenneth R - - 2008
Although all cells are variously affected by oxygen, a few have the responsibility of monitoring oxygen tensions and initiating key homeostatic responses when P(O2) falls to critical levels. These ;oxygen-sensing' cells include the chemoreceptors in the gills (neuroepithelial cells), airways (neuroepithelial bodies) and vasculature (carotid bodies) that initiate cardiorespiratory reflexes, ...
Otsu Kaoru - - 2008
Endoperoxides of naphthalene derivatives generate singlet oxygen under physiological conditions. Here we have synthesized a new endoperoxide of a naphthalene derivative, 1-buthylnaphthalene-4-propionate endoperoxide (BNPE), and studied its cytotoxic properties on HepG2 and HaCaT cells. BNPE induced cell death at much lower concentration than 1-methylnaphthalene-4-propionate endoperoxide (MNPE) and naphthalene dipropionate endoperoxide ...
Shen Jiangang - - 2008
Neuroblastoma cells are capable of hypoxic adaptation, but the mechanisms involved are not fully understood. We hypothesized that caveolin-1 (cav-1), a plasma membrane signal molecule, might play a role in protecting neuroblastoma cells from oxidative injury by modulating nitric oxide (NO) production. We investigated the alterations of cav-1, cav-2, nitric ...
Gong, Yanming
The oxygen reduction reaction (ORR) activity on the cathode plays a significant role in deciding the overall performance of proton exchange membrane (PEM) fuel cells. Dramatic effort has been devoted to the attempt to enhance the catalytic activity and reduce the overpotential caused by the irreversible oxygen reduction reaction on ...
Yoshiba Sayaka S Department of Oral and Maxillofacial Surgery, School of Dentistry, Showa University, Kitasenzoku 2-1-1, Ohta-ku, Tokyo 145-8515, Japan. - - 2009
Malignant tumors are exposed to various levels of hypoxic condition in vivo. It has been known that tumor cells under hypoxia are resistant to chemotherapies. To clarify the mechanism of the hypoxia-induced chemoresistance, we evaluated the effects of hypoxia on the resistance of oral squamous cell carcinoma (OSCC) cell lines ...
Busk Morten - - 2008
PURPOSE: Tumour hypoxia and elevated glycolysis (Warburg effect) predict poor prognosis. Each parameter is assessable separately with positron emission tomography, but they are linked through anaerobic glycolysis (Pasteur effect). Here, we compare the oxygenation-dependent retention of fluoroazomycin arabinoside ([(18)F]FAZA), a promising but not well-characterised hypoxia-specific tracer, and fluorodeoxyglucose ([(18)F]FDG) in ...
Dey Swatee S Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Health Sciences Research Building 454, Lexington, KY 40536-0298, - - 2008
The physicochemical properties of nanomaterials differ from those of the bulk material of the same composition. However, little is known about the underlying effects of these particles in carcinogenesis. The purpose of this study was to determine the mechanisms involved in the carcinogenic properties of nanoparticles using aluminum oxide (Al(2)O(3)/alumina) ...
Hanley Cory - - 2008
Nanoparticles are increasingly being recognized for their potential utility in biological applications including nanomedicine. Here we examine the response of normal human cells to ZnO nanoparticles under different signaling environments and compare it to the response of cancerous cells. ZnO nanoparticles exhibit a strong preferential ability to kill cancerous T ...
Venkatesha Venkatasubbaiah A VA Free Radical and Radiation Biology Program, B180 Medical Laboratories, Department of Radiation Oncology, The University of Iowa, Iowa City, IA 52242-1181, - - 2008
Polychlorinated biphenyls (PCBs) are environmental chemical contaminants believed to adversely affect cellular processes. We investigated the hypothesis that PCB-induced changes in the levels of cellular reactive oxygen species (ROS) induce DNA damage resulting in cytotoxicity. Exponentially growing cultures of human nonmalignant breast epithelial cells (MCF10A) were incubated with PCBs for ...
Zou Yanping - - 2008
Three phlorotannins, including phloroglucinol, diphlorethohydroxycarmalol, and 6,6'-bieckol, were isolated from Ishige okamurae by column chromatography. The structures of the phlorotannins were determined on the basis of spectroscopic analysis, including NMR and mass spectrometry (MS) techniques. Antioxidant effects of phlorotannins were measured by direct free radical scavenging activities using the electron ...
Schmid-Brunclik Nicole - - 2008
Hypoxia is linked to changes in blood-brain barrier (BBB) permeability, and loss of BBB integrity is characteristic of many pathological brain diseases including stroke. In particular, astrocytes play a central role in brain homeostasis and BBB function. We investigated how hypoxia affects astrocyte survival and assessed whether VEGF release through ...
Zegura Bojana - - 2008
Microcystins, which are hepatotoxins produced by cyanobacteria, have been reported to be potent tumour promoters, and there is an indication that they can also act as tumour initiators. They thus constitute a potential threat to human and animal health, at concentrations that do not cause acute hepatotoxic effects. The main ...
Robinson John M - - 2008
Phagocytic leukocytes consume oxygen and generate reactive oxygen species in response to appropriate stimuli. The phagocyte NADPH oxidase, a multiprotein complex, existing in the dissociated state in resting cells becomes assembled into the functional oxidase complex upon stimulation and then generates superoxide anions. Biochemical aspects of the NADPH oxidase are ...
Kolarova H - - 2008
The objectives of this study was to investigate the production of reactive oxygen species (ROS) after photodynamic therapy (PDT) in vitro. We examined second generation sensitizers, porphyrines (TPPS4, ZnTPPS4 and PdTPPS4) and compared their effectivity on ROS generation in G361 cell line. Used porphyrines are very efficient water-soluble aromatic dyes ...
Milovanova Tatyana T Institute For Environmental Medicine, University of Pennsylvania Medical Center, One John Morgan Building, Philadelphia, PA 19104-6068, - - 2008
Abrupt cessation of flow representing the acute loss of shear stress (simulated ischemia) to flow-adapted pulmonary microvascular endothelial cells (PMVEC) leads to reactive oxygen species (ROS) generation that signals for EC proliferation. We evaluated the role of caveolin-1 on this cellular response with mouse PMVEC that were preconditioned for 72 ...
Chen Chung-Yi - - 2008
In this study, we investigate the anticancer effect of isoobtusilactone A (IOA), a constituent isolated from the leaves of Cinnamomum kotoense, on human non-small cell lung cancer (NSCLC) A549 cells. IOA was found to induce the arrest of G2-M phase, induce apoptosis, increase sub-G1, and inhibit the growth of these ...
Dutta Sujoy - - 2008
Inherent deficiencies of Leishmania in heme biosynthesis were genetically complemented for delta-aminolevulinate-inducible biosynthesis and accumulation of light-excitable uroporphyrin. The phototoxic flagellar immobilization and cytolysis phenotypes and porphyrin mobilization noted previously were further analyzed biochemically and cytologically to delineate the mechanism of phototoxicity and detoxification in this monoporphyric model. Under optimal ...
Prata Cecilia - - 2008
The discovery of superoxide-generating enzymes homologues of phagocytic NAD(P)H oxidase, the Nox family, has led to the concept that reactive oxygen species (ROS) are 'intentionally' generated with biological functions in various cell types. In this study, by treating an acute leukaemic cell line with different antioxidants, ROS generation was shown ...
Kim Woo Hyang - - 2008
Vibrio vulnificus, a pathogenic bacterium causing primary septicemia, exhibited cytotoxicity towards Jurkat cells of T-lymphocytes through intracellular reactive oxygen species (ROS) production. Pretreatment of Jurkat T-cells with diphenyleneiodonium chloride (DPI) abolished V. vulnificus-induced ROS generation and bacterial ability to cause cell death. Jurkat T-cells expressing dominant-negative protein of Rac subunit ...
Kamnev Alexander A - - 2008
For the rhizobacterium Azospirillum brasilense, the optimal nutritional range of C:N ratios corresponds to the presence of malate (ca. 3 to 5 g l(-1) of its sodium salt) and ammonium (ca. 0.5 to 3 g l(-1) of NH4Cl) as preferred carbon and nitrogen sources, respectively. This microaerophilic aerotactic bacterium is ...
You Dong - - 2008
We analyzed the effect of hypertension on postischemic vasculogenesis. Ischemia was induced by right femoral artery ligature in Wistar Kyoto rats (WKY) or spontaneously hypertensive rats (SHR) treated with or without angiotensin-converting enzyme inhibitor (Perindopril, 0.76 mg/kg/d) and angiotensin type 1 receptor blocker (losartan, 30 mg/kg/d). Basal postischemic neovascularization was ...
Gonorazky Gabriela - - 2008
Various phosphoinositides have been implicated in plant defence signalling. Until now, such molecules have been exclusively related to intracellular signalling. Here, evidence is provided for the detection of extracellular phosphatidylinositol 4-phosphate (PI4P) in tomato cell suspensions. We have analysed and compared the intracellular and extracellular phospholipid profiles of [(32)P(i)]-prelabelled tomato ...
de Carvalho Daniela D - - 2008
The catalytic subunit of the NADPH oxidase complex, Nox1 (homologue of gp91phox/Nox2), expressed mainly in intestinal epithelial and vascular smooth muscle cells, functions in innate immune defense and cell proliferation. The molecular mechanisms underlying these functions, however, are not completely understood. We measured Nox1-dependent O2- production during cell spreading on ...
Koritsiadis George - - 2008
OBJECTIVE: To investigate the tissue distribution of ischaemia in human detrusor in patients with bladder outlet obstruction (BOO) and to correlate the results with clinical variables, as clinical BOO is a common problem in ageing men and ischaemia might be important in detrusor dysfunction. PATIENTS AND METHODS: From September 2004 ...
López-Lázaro Miguel - - 2008
Cells can obtain energy through the oxygen-dependent pathway of oxidative phosphorylation (OXPHOS) and through the oxygen-independent pathway of glycolysis. Since OXPHOS is more efficient in generating ATP than glycolysis, it is recognized that the presence of oxygen results in the activation of OXPHOS and the inhibition of glycolysis (Pasteur effect). ...
Naumenko E A - - 2008
The exposure of Bacillus cereus ZS18 cell suspensions to 2,4,6-trinitrotoluene (TNT) in the absence of other oxidizable substrates increases oxygen uptake, exceeding the basal level of respiration of the bacterium 1.5- and 2-fold with 50 and 100 mg/liter of TNT, respectively. The interaction of both living and to less extent ...
Theegala Chandra S - - 2008
Design and performance of an amperometric biosensor for E. coli O157:H7 that is based on a common dissolved oxygen probe is discussed. Anti-E. coli O157:H7 antibody was conjugated to horseradish peroxidase and immobilized on a nitrocellulose membrane that was placed over the oxygen probe membrane using a custom-fabricated polyvinyl chloride ...
Zahm Adam M AM Department of Orthopaedic Surgery, Thomas Jefferson University, Philadelphia, PA 19107, - - 2008
Oxygen availability is a critical signal for proper development of many tissues, however there is limited knowledge of its role in the maturation of bone cells. To test the hypothesis that low pO2 regulates bone cell mineralization, MLO-A5 and MLO-Y4 cells were cultured in monolayer and three-dimensional alginate scaffolds in ...
Boylan Julie A - - 2008
Spirochetes living in an oxygen-rich environment or when challenged by host immune cells are exposed to reactive oxygen species (ROS). These species can harm/destroy cysteinyl residues, iron-sulphur clusters, DNA and polyunsaturated lipids, leading to inhibition of growth or cell death. Because Borrelia burgdorferi contains no intracellular iron, DNA is most ...
Teranishi Shinichiro - - 2008
PURPOSE: The possible detrimental effect of hypoxia on the barrier function of corneal epithelial cells and whether keratinocyte growth factor (KGF) might protect against such an effect were investigated. METHODS: Simian virus 40-transformed human corneal epithelial (HCE) cells were cultured for 4 days to allow the establishment of barrier function. ...
Jacobsen Nicklas Raun - - 2008
The particulate phase of diesel engine exhaust is likely carcinogenic. However, the mechanisms of diesel exhaust particles (DEPs) induced mutagenicity/carcinogenicity are still largely unknown. We determined the mutant frequency following eight repeated 72 h incubations with 37.5 or 75 microg/ml DEP (NIST SRM 1650) in the FE1-MutaMouse lung epithelial cell ...
Apostolova, Nadezda
The apoptotic function of Apoptosis-inducing factor (AIF) is well documented in the literature, but its physiological role in the mitochondrion is less certain. Using a small interfering RNA (siRNA) strategy, we studied whether modulation of AIF expression in cultured cells influenced the production of reactive oxygen species (ROS). We found ...
Foreman Brooke D - - 2008
para-aminophenol (PAP) causes nephrotoxicity by biochemical mechanisms that have not been fully elucidated. PAP can undergo enzymatic or non-enzymatic oxidation to form reactive intermediates. Using modulators of reactive oxygen species (ROS), the role of ROS in PAP toxicity in LLC-PK(1) cells was investigated. ROS formation was determined using a fluorescein ...
Scharff Peter - - 2008
An increase of the intracellular reactive oxygen species (ROS) concentration leads to the development of oxidative stress and, thus, to the damage of cell components. The cause-and-effect relations between these processes have not been fully established yet. The ability of photo excited supramolecular composites containing fullerenes C60 immobilized at nanosilica ...
Na Ah Ram - - 2008
Low levels of endogenous reactive oxygen species (ROS) originating from NADPH oxidase have been implicated in various signaling pathways induced by growth factors and mediated by cytokines. However, the main source of ROS is known to be the mitochondria, and increased levels of ROS from the mitochondria have been observed ...
Neuzil, Jiri
Malignant mesothelioma (MM) cells enhanced proliferation of endothelial cells (ECs) as well as their angiogenesis in vitro by secretion of fibroblast growth factor-2 (FGF2). This effect was suppressed by pre-treating MM cells with greek small letter alpha-tocopheryl succinate (greek small letter alpha-TOS), which inhibited FGF2 secretion by inducing mitochondria-dependent generation ...
Chin Kyuongsik - - 2008
Cell encapsulation provides cells a three-dimensional structure to mimic physiological conditions and improve cell signaling, proliferation, and tissue organization as compared to monolayer culture. Encapsulation devices often encounter poor mass transport, especially for oxygen, where critical dissolved levels must be met to ensure both cell survival and functionality. To enhance ...
Bernal Ibáñez, María
http://www.blackwell-synergy.com/links/doi/10.1111/j.1399-3054.2006.00641.x
Taguchi Keiko - - 2008
9,10-Phenanthraquinone (PQ), a component of airborne particulate matter, causes marked cellular protein oxidation and cytotoxicity through a two-electron reduction to 9,10-dihydroxyphenanthrene (PQH2), which is associated with the propagation of reactive oxygen species (K. Taguchi et al., Free Radic. Biol. Med. 43:789-799, 2007). In the present study, we explored a biotransformation ...
Kaur Parvinder - - 2008
The effect of methylmercury (MeHg) on reactive oxygen species (ROS) induction in neural cell lines was measured by the fluorescent probe, chloro methyl derivative of di-chloro di-hydro fluoresceindiacetate (CMH2DCFDA). Three different MeHg concentrations (5, 10 and 25 microM) and time periods (30, 50 and 90 min) were studied in C6-glial ...
Azevedo Herlânder - - 2008
Models of non-host resistance have failed to account for the pathogenicity of necrotrophic agents. During the interaction of Pinus pinaster (maritime pine) with the non-host necrotrophic pathogen Botrytis cinerea, the generation and scavenging of reactive oxygen species (ROS) and the induction of the hypersensitive response (HR) were analyzed. Elicitation of ...
Rharass Tareck - - 2008
Tumour hypoxia plays a role in chemoresistance in several human tumours. However, how hyperbaric oxygen leads to chemotherapeutic gain is unclear. This study investigates the relation of reactive oxygen species (ROS) generation with anti-tumoural effect of adriamycin (ADR) on CCRF-CEM cells under hypoxic (2% O(2)) and normoxic (21% O(2)) conditions. ...
McDermott Catherine - - 2008
Here we assess the role of reactive oxygen species (ROS) formation in the manifestation of n-hexane toxicity in Jurkat T-cells and the chemo-protective potential of the antioxidants epigallocatechin-3-gallate (EGCG) and thymoquinone (TQ) against n-hexane toxicity in vitro. n-Hexane is an important industrial solvent and ambient air pollutant. Subchronic exposure to ...
Suzuki Tsukasa - - 2008
The products of the TSC1 (hamartin) and TCS2 (tuberin) tumor suppressor genes negatively regulate cell growth by inhibiting mTOR signaling. Recent research has led to the postulation that tuberin and/or hamartin are involved in tumor migration, presumably through Rho activation. Here we show that LEF-8 cells, which contain a Y1571 ...
Coelho, M. A. Z.
The effects of hyperbaric stress on the morphology of Saccharomyces cerevisiae were studied in batch cultures under pressures between 0.1 MPa and 0.6 MPa and different gas compositions (air, O2, N2, or CO2), covering aerobic and anaerobic conditions. A method using automatic image analysis for cell classification based on their ...
Chow Jyh-Ming - - 2008
We investigate the cytotoxic effect of metal protoporphyrins including ferric protoporphyrin (FePP; hemin), cobalt protoporphyrin (CoPP), and tin protoporphyrin (SnPP) in glioblastoma cells C6 and GBM8401. Data of MTT assay show that FePP and CoPP, but not SnPP, significantly reduce the viability of glioma cells C6 and GBM8401 in the ...
Borthiry Griselda R - - 2008
Chromium(VI) compounds (e.g. chromates) are cytotoxic, mutagenic, and potentially carcinogenic. The reduction of Cr(VI) can yield reactive intermediates such as Cr(V) and reactive oxygen species. Bronchial epithelial cells are the primary site of pulmonary exposure to inhaled Cr(VI) and are the primary cells from which Cr(VI)-associated human cancers arise. BEAS-2B ...
Kim Hyung Woo - - 2010
Reactive oxygen species (ROS) have been implicated in the pathogenesis of a wide range of acute and long-term neurodegenerative diseases. This study was undertaken to examine the efficacy of Pogostemon cablin, a well-known herb in Korean traditional medicine, on ROS-induced brain cell injury. Pogostemon cablin effectively protected human neuroglioma cell ...
Stuckey, Crystal Elaine
Regulation of normal volume is an important aspect of cell homeostasis. Possible mechanisms which signal volume regulation are increasing the rate of reactive oxygen species (ROS) production and release of ATP for interaction with purinergic receptors. We examined whether an increase in ROS production during cell swelling also led to ...
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