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Potential Candidates (potential + candidate)
Terms modified by Potential Candidates Selected AbstractsEmpirical evidence of underutilization of referrals for epilepsy surgery evaluationEUROPEAN JOURNAL OF NEUROLOGY, Issue 4 2010P. De Flon Background:, Epilepsy surgery is a treatment that can cure patients with intractable epilepsy. This study investigates whether referrals for epilepsy surgery evaluation are underutilized. Methods:, Patients with epilepsy aged 18,60 years were identified in a computerized registry held by public health care providers in a Swedish county using ICD codes. Clinical data and data on referral status for epilepsy surgery were obtained from the patients' medical records. Potential candidates for epilepsy surgery evaluation were identified using pre-specified criteria. Obstacles for referral were analysed by comparing clinical data in patients who were considered for referral and those who were not. Appropriateness of non-referral was evaluated against recommendations from the Swedish Council on Technology in Health Care (SBU). Results:, Of 378 patients with epilepsy in the registry, 251 agreed to participate. Of 251, 40 were already referred patients and 48 patients were identified as potential candidates for epilepsy surgery evaluation by study criteria. Referral had been considered but not performed in 15 of the potential candidates. Potential candidates not considered for referral were less likely to have seen a neurologist, to have had an EEG, CT and MRI, and more likely to have cognitive disturbances. Following the recommendations by the SBU, 28 of 48 potential candidates were identified as inappropriately not referred patients. Conclusion:, The number of missed referrals for epilepsy surgery evaluation was estimated to be 60 per 100 000 inhabitants. Several important obstacles were found for not referring patients for epilepsy surgery evaluation. [source] Connective tissue growth factor and cardiac fibrosisACTA PHYSIOLOGICA, Issue 3 2009A. Daniels Abstract Cardiac fibrosis is a major pathogenic factor in a variety of cardiovascular diseases and refers to an excessive deposition of extracellular matrix components in the heart, which leads to cardiac dysfunction and eventually overt heart failure. Evidence is accumulating for a crucial role of connective tissue growth factor (CTGF) in fibrotic processes in several tissues including the heart. CTGF orchestrates the actions of important local factors evoking cardiac fibrosis. The central role of CTGF as a matricellular protein modulating the fibrotic process in cardiac remodelling makes it a possible biomarker for cardiac fibrosis and a potential candidate for therapeutic intervention to mitigate fibrosis in the heart. [source] NaV1.6a is required for normal activation of motor circuits normally excited by tactile stimulationDEVELOPMENTAL NEUROBIOLOGY, Issue 7 2010Sean E. Low Abstract A screen for zebrafish motor mutants identified two noncomplementing alleles of a recessive mutation that were named non-active (navmi89 and navmi130). nav embryos displayed diminished spontaneous and touch-evoked escape behaviors during the first 3 days of development. Genetic mapping identified the gene encoding NaV1.6a (scn8aa) as a potential candidate for nav. Subsequent cloning of scn8aa from the two alleles of nav uncovered two missense mutations in NaV1.6a that eliminated channel activity when assayed heterologously. Furthermore, the injection of RNA encoding wild-type scn8aa rescued the nav mutant phenotype indicating that scn8aa was the causative gene of nav. In-vivo electrophysiological analysis of the touch-evoked escape circuit indicated that voltage-dependent inward current was decreased in mechanosensory neurons in mutants, but they were able to fire action potentials. Furthermore, tactile stimulation of mutants activated some neurons downstream of mechanosensory neurons but failed to activate the swim locomotor circuit in accord with the behavioral response of initial escape contractions but no swimming. Thus, mutant mechanosensory neurons appeared to respond to tactile stimulation but failed to initiate swimming. Interestingly fictive swimming could be initiated pharmacologically suggesting that a swim circuit was present in mutants. These results suggested that NaV1.6a was required for touch-induced activation of the swim locomotor network. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 70:508,522, 2010 [source] Phytotoxicity and phytoaccumulation of trivalent and hexavalent chromium in brake fernENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2005Yi Su Abstract A recently recognized hyperaccumulator plant, Chinese brake fern (Pteris vittata), has been found to extract very high concentration of arsenic from arsenic-contaminated soil. Chromium usually is a coexisting contaminant with arsenic in most contaminated soils. The potential application of ferns for phytoremediation of chromium(III)- and chromium(VI)-contaminated soils and their phytotoxicity to ferns has not been studied before. In this study, chromium distribution and phytotoxicity at the plant and cellular levels of brake ferns were studied using chemical analyses and scanning electron microscopy. The results show a higher phytotoxicity of Cr from Cr(VI)-contaminated soil to Chinese brake fern than from Cr(III)-contaminated soil. Phytotoxicity symptoms included significant decreases both in fresh biomass weight and relative water content (RWC), and also in leaf chlorosis during the late stage of growing. At higher concentrations (500 mg/kg Cr[VI] and 1,000 mg/kg Cr[III] addition), plants showed reduction in the number of palisade and spongy parenchyma cells in leaves. Compared with other plant species reported for phytoremediation of Cr(VI)-contaminated soil, brake fern took up and accumulated significant amounts of Cr (up to 1,145 mg/kg in shoots and 5,717 mg/kg in roots) and did not die immediately from phytotoxicity. Our study suggests that Chinese brake fern is a potential candidate for phytoremediation of Cr(VI)-contaminated soils, even though plants showed severe phytotoxic symptoms at higher soil Cr concentrations. [source] Expression of GITR ligand abrogates immunosuppressive function of ocular tissue and differentially modulates inflammatory cytokines and chemokinesEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 8 2006Sankaranarayana Abstract The glucocorticoid-induced TNF-related receptor ligand (GITRL) was previously shown to be constitutively expressed at low levels in human eye, including retinal pigment epithelial (RPE) cells. By expressing enhanced yellow fluorescent protein-tagged human GITRL in human RPE cells, we investigated the significance of expression of GITRL on human ocular tissue. Confocal immunofluorescence microscopy and flow cytometry confirmed the surface expression of GITRL on RPE cells. However, a soluble form of GITRL was also detected. Remarkably, expression of GITRL on the RPE cells abrogated RPE-mediated immunosuppression of CD3+ T cells, implicated as a possible mechanism for ocular immune privilege. This abrogation of immunosuppression by GITRL-RPE was dependent on GITR-GITRL interaction and could not be mimicked by anti-CD28 antibody. Analysis of cytokine profiles revealed high level of TGF-beta during the immunosuppression by RPE cells while expression of GITRL abrogated the RPE cell-induced TGF-beta secretion. Expression of GITRL also stimulates secretion of an array of proinflammatory cytokines/chemokines from T cells. GITR-GITRL interaction provides a unique proinflammatory costimulation that may signal through a different pathway than that of CD28-B7 costimulation. This study implicated that GITRL could be a potential candidate for regulation of the ocular immune privilege and the balance between immune privilege and inflammation. [source] Topical ascorbic acid on photoaged skin.EXPERIMENTAL DERMATOLOGY, Issue 3 2003Clinical, topographical, ultrastructural evaluation: double-blind study vs. placebo Abstract:, Vitamin C is known for its antioxidant potential and activity in the collagen biosynthetic pathway. Photoprotective properties of topically applied vitamin C have also been demonstrated, placing this molecule as a potential candidate for use in the prevention and treatment of skin ageing. A topically applied cream containing 5% vitamin C and its excipient were tested on healthy female volunteers presenting with photoaged skin on their low-neck and arms in view to evaluate efficacy and safety of such treatment. A double-blind, randomized trial was performed over a 6-month period, comparing the action of the vitamin C cream vs. excipient on photoaged skin. Clinical assessments included evaluation at the beginning and after 3 and 6 months of daily treatment. They were performed by the investigator and compared with the volunteer self assessment. Skin relief parameters were determined on silicone rubber replicas performed at the same time-points. Cutaneous biopsies were obtained at the end of the trial and investigated using immunohistochemistry and electron microscopy. Clinical examination by a dermatologist as well as self-assessment by the volunteers disclosed a significant improvement, in terms of the ,global score', on the vitamin C-treated side compared with the control. A highly significant increase in the density of skin microrelief and a decrease of the deep furrows were demonstrated. Ultrastructural evidence of the elastic tissue repair was also obtained and well corroborated the favorable results of the clinical and skin surface examinations. Topical application of 5% vitamin C cream was an effective and well-tolerated treatment. It led to a clinically apparent improvement of the photodamaged skin and induced modifications of skin relief and ultrastructure, suggesting a positive influence of topical vitamin C on parameters characteristic for sun-induced skin ageing. [source] Preparation of Uniform, Water-Soluble, and Multifunctional Nanocomposites with Tunable SizesADVANCED FUNCTIONAL MATERIALS, Issue 5 2010Dechao Niu Abstract Novel, thiol-functionalized, and superparamagnetic, silica composite nanospheres (SH-SSCNs) with diameters smaller than 100,nm are successfully fabricated through the self-assembly of Fe3O4 nanoparticles and polystyrene100 - block -poly(acrylic acid)16 and a subsequent sol-gel process. The size and magnetic properties of the SH-SSCNs can be easily tuned by simply varying the initial concentrations of the magnetite nanoparticles in the oil phase. By incorporating fluorescent dye molecules into the silica network, the composite nanospheres can be further fluorescent-functionalized. The toxicity of the SH-SSCNs is evaluated by choosing three typical cell lines (HUVEC, RAW264.7, and A549) as model cells, and no toxic effects are observed. It is also demonstrated that SH-SSCNs can be used as a new class of magnetic resonance imaging (MRI) probes, having a remarkably high spin,spin (T2) relaxivity (r2*,=,176.1,mM,1 S,1). The combination of the sub-100-nm particle size, monodispersity in aqueous solution, superparamagnetism, and fluorescent properties of the SH-SSCNs, as well as the non-cytotoxicity in vitro, provides a novel and potential candidate for an earlier MRI diagnostic method of cancer. [source] PEI,PEG,Chitosan-Copolymer-Coated Iron Oxide Nanoparticles for Safe Gene Delivery: Synthesis, Complexation, and TransfectionADVANCED FUNCTIONAL MATERIALS, Issue 14 2009Forrest M. Kievit Abstract Gene therapy offers the potential of mediating disease through modification of specific cellular functions of target cells. However, effective transport of nucleic acids to target cells with minimal side effects remains a challenge despite the use of unique viral and non-viral delivery approaches. Here, a non-viral nanoparticle gene carrier that demonstrates effective gene delivery and transfection both in vitro and in vivo is presented. The nanoparticle system (NP,CP,PEI) is made of a superparamagnetic iron oxide nanoparticle (NP), which enables magnetic resonance imaging, coated with a novel copolymer (CP,PEI) comprised of short chain polyethylenimine (PEI) and poly(ethylene glycol) (PEG) grafted to the natural polysaccharide, chitosan (CP), which allows efficient loading and protection of the nucleic acids. The function of each component material in this nanoparticle system is illustrated by comparative studies of three nanoparticle systems of different surface chemistries, through material property characterization, DNA loading and transfection analyses, and toxicity assessment. Significantly, NP,CP,PEI demonstrates an innocuous toxic profile and a high level of expression of the delivered plasmid DNA in a C6 xenograft mouse model, making it a potential candidate for safe in vivo delivery of DNA for gene therapy. [source] DNA Sensors: Highly Sensitive, Mechanically Stable Nanopore Sensors for DNA Analysis (Adv. Mater.ADVANCED MATERIALS, Issue 27 200927/2009) A new solid state nanopore biosensor for the analysis of individual DNA molecules is reported by Rashid Bashir and co-workers on p. 2771. The cover illustrates the passage of double-stranded DNA through an Al2O3 nanopore sensor fabricated using ALD and e-beam-induced sputtering processes. Hexagonal ,-phase Al2O3 nanocrystallites form during pore formation as shown, improving the mechanical stability and sensitivity of these nanopore sensors. The CMOS-compatible nature of this process establishes this technology as a potential candidate for next-generation DNA sequencing. [source] Application of radial basis meshless methods to direct and inverse biharmonic boundary value problemsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 4 2005Jichun Li Abstract In this paper, we develop a non-iterative way to solve biharmonic boundary value problems by using a radial basis meshless method. This is an original application of meshless method to solving inverse problems without any iteration, since traditional numerical methods for inverse boundary value problems mainly are iterative and hence very time-consuming. Numerical examples are presented for inverse biharmonic boundary value problems and corresponding direct problems, since solving direct problems is a preliminary step for inverse problems. All our examples of direct and inverse problems are solved within seconds in CPU time on a standard PC, which makes our proposed technique a great potential candidate for wide-spread applications to other inverse problems. Copyright © 2004 John Wiley & Sons, Ltd. [source] Is Leptin the Link Between Fat and Bone Mass?,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 9 2002Thierry Thomas Ph.D. Abstract Recently, leptin has emerged as a potential candidate responsible for protective effects of fat on bone tissue. However, it remains difficult to draw a clear picture of leptin effects on bone metabolism because published data are sometimes conflicting or apparently contradictory. Beyond differences in models or experimental procedures, it is tempting to hypothesize that leptin exerts dual effects depending on bone tissue, skeletal maturity, and/or signaling pathway. Early in life, leptin could stimulate bone growth and bone size through direct angiogenic and osteogenic effects on stromal precursor cells. Later, it may decrease bone remodeling in the mature skeleton, when trabecular bone turnover is high, by stimulating osteoprotegerin (OPG) expression. Leptin negative effects on bone formation effected through central nervous system pathway could counterbalance these peripheral and positive effects, the latter being predominant when the blood-brain barrier permeability decreases or the serum leptin level rises above a certain threshold. Thus, the sex-dependent specificity of the relationship between leptin and bone mineral density (BMD) in human studies could be, at least in part, caused by serum leptin levels that are two- to threefold higher in women than in men, independent of adiposity. Although these hypotheses remain highly speculative and require further investigations, existing studies consistently support the role of leptin as a link between fat and bone. [source] Improved outcome of EAN, an animal model of GBS, through amelioration of peripheral and central inflammation by minocyclineJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 2 2009Zhi-Yuan Zhang Abstract Experimental autoimmune neuritis (EAN) is a widely used animal model of the human acute inflammatory demyelinating polyradiculoneuropathy, which is the most common subtype of Guillain-Barré Syndrome. EAN is pathologically characterized by breakdown of the blood-nerve barrier, infiltration of reactive immune cells, local inflammation, demyelination in the peripheral nervous system and mechanical allodynia. Minocycline is known to have neuroprotective and anti-inflammatory effects. Furthermore, relieve of neuropathic pain following minocycline administration was observed in a variety of animal models. Here, we investigated the effects of minocycline on rat EAN. Suppressive treatment with minocycline (50 mg/kg body weight daily immediately after immunization) significantly attenuated the severity and duration of EAN. Macrophage and T-cell infiltration and demyelination in sciatic nerves of EAN rats treated with minocycline were significantly reduced compared to phosphate-buffered saline (PBS)-treated EAN rats. mRNA expressions of matrix metallopeptidase-9, inducible nitric oxide synthase and pro-inflammatory cytokines interleukin-1 , and tumour necrosis factor-, in EAN sciatic nerves were greatly decreased by administration of minocycline as well. Furthermore, minocycline attenuated mechanical allodynia in EAN rats and greatly suppressed spinal microglial activation. All together, our data showed that minocycline could effectively suppress the peripheral and spinal inflammation (immune activation) to improve outcome in EAN rats, which suggests that minocycline may be considered as a potential candidate of pharmacological treatment for autoimmune-mediated neuropathies. [source] Mechanistic study of saikosaponin-d (Ssd) on suppression of murine T lymphocyte activationJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2009Vincent Kam Wai Wong Abstract Saikosaponin-d (Ssd) is a triterpene saponin derived from the medicinal plant, Bupleurum falcatum L. (Umbelliferae). Previous findings showed that Ssd exhibits a variety of pharmacological and immunomodulatory activities including anti-inflammatory, anti-bacterial, anti-viral and anti-cancer effects. In the current study we have investigated the effects of Ssd on activated mouse T lymphocytes through the NF-,B, NF-AT and AP-1 signaling pathways, cytokine secretion, and IL-2 receptor expression. The results demonstrated that Ssd not only suppressed OKT3/CD28-costimulated human T cell proliferation, it also inhibited PMA, PMA/Ionomycin and Con A-induced mouse T cell activation in vitro. The inhibitory effect of Ssd on PMA-induced T cell activation was associated with down-regulation of NF-,B signaling through suppression of IKK and Akt activities. In addition, Ssd suppressed both DNA binding activity and the nuclear translocation of NF-AT and activator protein 1 (AP-1) of the PMA/Ionomycin-stimulated T cells. The cell surface markers like IL-2 receptor (CD25) were also down-regulated together with decreased production of pro-inflammatory cytokines of IL-6, TNF-, and IFN-,. These results indicate that the NF-,B, NF-AT and AP-1 (c-Fos) signaling pathways are involved in the T cell inhibition evoked by Ssd, so it can be a potential candidate for further study in treating T cell-mediated autoimmune conditions. J. Cell. Biochem. 107: 303,315, 2009. © 2009 Wiley-Liss, Inc. [source] Possible Role of Oestrogen in Pubertal Increase of Kiss1/Kisspeptin Expression in Discrete Hypothalamic Areas of Female RatsJOURNAL OF NEUROENDOCRINOLOGY, Issue 6 2009K. Takase Kisspeptin, a peptide encoded by the Kiss1 gene, has been considered as a potential candidate for a factor triggering the onset of puberty, and its expression in the hypothalamus was found to increase during peripubertal period in rodent models. The present study aimed to clarify the oestrogenic regulation of peripubertal changes in Kiss1 mRNA expression in the anteroventral periventricular nucleus (AVPV) and hypothalamic arcuate nucleus (ARC), and to determine which population of kisspeptin neurones shows a change in kisspeptin expression parallel to that in luteinising hormone (LH) pulses at the peripubertal period. Quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry revealed an apparent increase in the ARC Kiss1 mRNA expression and kisspeptin immunoreactivity around the time of vaginal opening in intact female rats. The AVPV Kiss1 mRNA levels also increased at day 26, but decreased at day 31, and then increased at day 36/41. In ovariectomised (OVX) rats, ARC Kiss1 mRNA expression did not show peripubertal changes and was kept at a high level throughout peripubertal periods. Apparent LH pulses were found in these prepubertal OVX rats. Oestradiol replacement suppressed ARC Kiss1 mRNA expression in OVX prepubertal rats, but not in adults. Similarly, LH pulses were suppressed by oestradiol in the prepubertal period (days 21 and 26), but regular pulses were found in adulthood. The present study suggests that a pubertal increase of Kiss1/kisspeptin expression both in the ARC and AVPV is involved in the onset of puberty. These results also suggest that both LH pulses and ARC Kiss1 expression are more negatively regulated by oestrogen in prepubertal female rats compared to adult rats. [source] Neuromedin U in the Paraventricular and Arcuate Hypothalamic Nuclei Increases Non-Exercise Activity ThermogenesisJOURNAL OF NEUROENDOCRINOLOGY, Issue 8 2006C. M. Novak Brain neuromedin U (NMU) has been associated with the regulation of both energy intake and expenditure. We hypothesized that NMU induces changes in spontaneous physical activity and nonexercise activity thermogenesis (NEAT) through its actions on hypothalamic nuclei. We applied increasing doses of NMU directly to the paraventricular (PVN) and arcuate hypothalamic nuclei using chronic unilateral guide cannulae. In both nuclei, NMU significantly and dose-dependently increased physical activity and NEAT. Moreover, NMU increased physical activity and NEAT during the first hour of the dark phase, indicating that the reduction of sleep is unlikely to account for the increased physical activity seen with NMU treatment. As a positive control, we demonstrated that paraventricular NMU also significantly decreased food intake, as well as body weight. These data demonstrate that NMU is positively associated with NEAT through its actions in the PVN and arcuate nucleus. In co-ordination with its suppressive effects on feeding, the NEAT-activating effects of NMU make it a potential candidate in the combat of obesity. [source] Unaltered neuropeptide Y (NPY)-stimulated [35S]GTP,S binding suggests a net increase in NPY signalling after repeated electroconvulsive seizures in miceJOURNAL OF NEUROSCIENCE RESEARCH, Issue 6 2006D.Z. Christensen Abstract Although electroconvulsive seizures (ECS) are widely used as a treatment for severe depression, the working mechanism of ECS remains unclear. Repeated ECS causes anticonvulsant effects that have been proposed to underlie the therapeutic effect of ECS, and neuropeptide Y (NPY) is a potential candidate for mediating this anticonvulsant effect. Repeated ECS results in prominent increases in NPY synthesis. In contrast, NPY-sensitive receptor binding is decreased, so it is unclear whether ECS causes a net increase in NPY signalling. Agonist-stimulated [35S]GTP,S binding is a method for detecting functional activation of G-protein-coupled receptors. The present study in mice examined the effects of daily ECS for 14 days on NPY-stimulated [35S]GTP,S functional binding and compared this with gene expression of NPY and NPY receptors as well as [125I]peptide YY (PYY) binding in hippocampus of the same animals. Significant increases in NPY mRNA and concomitant reductions in NPY-sensitive binding were found in the dentate gyrus, hippocampal CA1, and neocortex of ECS treated mice, which is consistent with previous rat data. These changes remained significant 1 week after repeated ECS. Significant increases in NPY Y1, Y2, and Y5 mRNA were found in the dentate gyrus after ECS. Surprisingly, unaltered levels of functional NPY receptor binding accompanied the decreased NPY-sensitive binding. This suggests that mechanisms coupling NPY receptor stimulation to G-protein activation could be augmented after repeated ECS. Thus increased synthesis of NPY after repeated ECS should result in a net increase in NPY signalling in spite of reduced levels of NPY-sensitive binding. © 2006 Wiley-Liss, Inc. [source] ETHANOL-INDUCED SUPEROXIDE RADICALS IN FETAL CORTICAL NEURONS: CELLULAR ROS NETWORKALCOHOLISM, Issue 2008Amina E Jamali Alcohol exposure to the developing brain compromises both neurons and glial functions. While neurons are considered the primary targets, microglia may play a neurotoxic role in this process. Previous studies demonstrated that neuron death is due to oxidative stress and mitochondrially mediated (Intrinsic). These studies showed a rapid increase (within minutes) in reactive oxygen species (ROS). Due to the diffusive nature of ethanol and multiple sources of free radicals, we sought to determine the primary source of superoxide targeted by ethanol. Confocal studies of neurons suggest that the superoxide radicals may originate from the mitochondria. Using whole neurons in a luminol-based chemiluminescence assay (Diogenes) we detected superoxide radicals in the extracellular mileu. We observed a two-three fold transient increase in the steady state generation of superoxide radicals between 20 minutes to one hour of ethanol exposure (4mg/ml). However, the presence of Rotenone (mitochondrial complex I inhibitor) and DPI (an inhibitor of all flavinoids) blocked the release of these superoxide radicals. Interestingly, cortical microglia treated identically with ethanol, showed a greater than five fold increase in superoxide generation with a maximum at one hour. Moreover, since ethanol is known to induce hydrogen peroxide generation, it was used as a mimetic. Hydrogen peroxide also induced the production of superoxide different time kinetics. Thus, together these data demonstrate that ethanol induces the steady state production of superoxide radicals in the extracellular mileu in a mitochondrial dependent manner. Since NOX2 an NADPH oxidase is expressed in neurons, it is a potential candidate for the secondary sites of superoxide generation. The ROS network between mitochondria and the plasma membrane highlights new therapeutical targets to counter ethanol toxicity. [source] Pressureless Rapid Sintering of UO2 Assisted by High-frequency Induction Heating ProcessJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 10 2008Jae Ho Yang Heat generation of uranium dioxide (UO2) powder and its pressureless rapid sintering behaviors have been studied using a high-frequency induction heating apparatus. The porous graphite housing has been used to prevent heat loss and to preheat the uranium oxides, simultaneously. At an elevated temperature, UO2 powder generated extra heat by itself. The synergism of individual heat generation between the graphite and UO2 powder could effectively heat the UO2 to the sintering temperature of 1700°C. Using this process, densification behavior of cylindrical and disk-type UO2 green pellets according to the heating rate and grain structure of sintered UO2 pellets were investigated. Rapid sintering caused a large crack around the circumference of the sintered pellet. The formation of cracks could be avoided when the heating rate or sample dimension are properly reduced. A dense and crack-free UO2 pellet with a relative density of up to 96% was produced within 5 min of the process time. The induction heat sintering process can be a potential candidate for the rapid fabrication of ceramics and composites. [source] Mechanism of insoluble phosphate solubilization by Pseudomonas fluorescens RAF15 isolated from ginseng rhizosphere and its plant growth-promoting activitiesLETTERS IN APPLIED MICROBIOLOGY, Issue 2 2009K.-H. Park Abstract Aims:, To investigate the mechanism of insoluble phosphate (P) solubilization and plant growth-promoting activity by Pseudomonas fluorescens RAF15. Methods and Results:, We investigated the ability of Ps. fluorescens RAF15 to solubilize insoluble P via two possible mechanisms: proton excretion by ammonium assimilation and organic acid production. There were no clear differences in pH and P solubilization between glucose-ammonium and glucose-nitrate media. P solubilization was significantly promoted with glucose compared to fructose. Regardless of nitrogen sources used, Ps. fluorescens RAF15 solubilized little insoluble P with fructose. High performance liquid chromatography analysis showed that Ps. fluorescens RAF15 produced mainly gluconic and tartaric acids with small amounts of 2-ketogluconic, formic and acetic acids. During the culture, the pH was reduced with increase in gluconic acid concentration and was inversely correlated with soluble P concentration. Ps. fluorescens RAF1 showed the properties related to plant growth promotion: pectinase, protease, lipase, siderophore, hydrogen cyanide, and indoleacetic acid. Conclusion:, This study indicated that the P solubility was directly correlated with the organic acids produced. Significance and Impact of the Study:,Pseudomonas fluorescens RAF15 possessed different traits related to plant growth promotion. Therefore, Ps. fluorescens RAF15 could be a potential candidate for the development of biofertilizer or biocontrol agent. [source] Modification of culture conditions for production of the anti-tubercular hirsutellones by the insect pathogenic fungus Hirsutella nivea BCC 2594LETTERS IN APPLIED MICROBIOLOGY, Issue 2 2008S. Madla Abstract Aims:, This work aimed to improve the production of anti-tubercular hirsutellones by the insect pathogenic fungus Hirsutella nivea BCC 2594. Methods and Results:, The fungus was cultivated under different carbon/nitrogen sources and aerations (shake vs static flasks) to improve the production of the anti-tubercular alkaloids, hirsutellones A,D. Under the basal conditions, static cultivation at 25°C in minimum salt medium, only hirsutellone B and C were detected with maximum concentrations of 139·00 and 18·27 mg l,1. Substitution of fructose for glucose and peptone for yeast extract increased the titres of hirsutellones A, B and C about two- to threefold. However, hirsutellone D was not detected in this medium. Culture agitation induced the production of hirsutellone D. As a result, the significant amounts of hirsutellones A,D were obtained with the concentration of 29·93, 169·63, 22·65 and 15·71 mg l,1 within 15 days. Conclusions:, Improved titres of hirsutellones in H. nivea BCC 2549 were achieved with an agitated (200 rev min,1) fructose,peptone medium at 25°C. Significance and Impact of the Study:, Improved yields of hirsutellones B,D will enable medicinal chemistry modifications leading to a development of a potential candidate for tuberculosis therapy. [source] Immunization with recombinant beta-tubulin from Trypanosoma evansi induced protection against T. evansi, T. equiperdum and T. b. brucei infection in micePARASITE IMMUNOLOGY, Issue 4 2007S.-Q. LI SUMMARY The beta-tubulin gene of Trypanosoma evansi (STIB 806) was cloned and expressed in Escherichia coli. The predicted amino acid sequence of T. evansi beta-tubulin shows 100%, 99·8%, 99·1%, and 98·6% homology with T. equiperdum, T. b. brucei, T. cruzi and T. danilewskyi, respectively, but is diverse from that of T. cyclops, showing only 51·6% of homology. Recombinant beta-tubulin was expressed as inclusion bodies in E. coli. It was purified and renatured for immunological studies. Mice immunized with the renatured recombinant beta-tubulin were protected from lethal challenge with T. evansi STIB 806, T. equiperdum STIB 818 and T. b. brucei STIB 940, showing 83·3%, 70% and 76·7% protection, respectively. Serum collected from the rabbit immunized with recombinant beta-tubulin inhibited the growth of T. evansi, T. equiperdum and T. b. brucei in vitro. Serum from mice and rabbits immunized with recombinant beta-tubulin recognized only T. evansi beta-tubulin and not mouse beta-tubulin. The results of this study demonstrated that the recombinant T. evansi beta-tubulin is a potential candidate for the development of a vaccine to prevent animal trypanosomiasis caused by these three trypanosome species. [source] Filling of carbon nanotubes for bio-applicationsPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 11 2007S. Costa Abstract Carbon nanotubes (CNT) provide a smart carrier system on the nanometer scale. The system can be used as a template for ferromagnetic fillers. Such a molecular hybrid is a promising potential candidate for the controlled heating of tumour tissue at the cellular level. This is a key reason why it is important to optimize the synthesis route of metal filled carbon nanotubes with regards bulk scale synthesis and purity. In the current study we present multiwalled carbon nanotubes filled with ,-iron phase (Fe-MWCNT). The influence of acid treatment on the stability of the filling and the sample purity is also presented. High resolution transmission microscopy, its Energy dispersive X-Ray spectroscopy (EDX) and electron energy-loss spectroscopy (EELS) modes have been applied for the analysis of the morphology and chemical composition of the samples. The phase of iron nanowires encapsulated into the carbon nanotubes was determined with selected area electron diffraction (SAED) on a local scale. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] High-frequency ferromagnetic properties of FeCoZr nanocrystalline filmsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2007Yung-Wang Peng Abstract FeCoZr magnetic thin films with high uni-axial anisotropy were fabricated by RF co-sputtering followed by post magnetic annealing. The crystal size of FeCoZr films was less than 15 nm, as calculated by Scherrer equation from X-ray diffraction patterns. By adding Zr element, FeCoZr films exhibited a uni-axial anisotropy after magnetic field annealing at 400 °C for 1 hr. Optimal high frequency ferromagnetic properties were achieved in film with 19 at.% Zr, in which strong uni-axial anisotropy field of 300 Oe and high ferromagnetic resonance frequency in excess of 5.2 GHz were obtained. These facts suggest that FeCoZr nano-crystalline film is a potential candidate in high frequency electromagnetic devices operating at GHz bands. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Radix Astragali extract promotes angiogenesis involving vascular endothelial growth factor receptor-related phosphatidylinositol 3-kinase/Akt-dependent pathway in human endothelial cellsPHYTOTHERAPY RESEARCH, Issue 9 2009Yi Zhang Abstract Angiogenesis plays an important role in a wide range of physiological processes and many diseases are associated with dysregulation of angiogenesis. Radix Astragali, commonly used in traditional Chinese medicine, is a potential candidate for treating such diseases. However, the biological effects of Radix Astragali on angiogenesis and its underlying mechanisms are yet to be elucidated fully. This study describes the angiogenic effects of Radix Astragali extract (RAE) on human umbilical vein endothelial cells (HUVEC) in vitro. It was shown that RAE treatment stimulated HUVEC to proliferate. A significant increase in migration was observed in RAE-treated HUVEC using the wound healing migration assay. In addition, a significant increase in the number of branching points was observed during endothelial cell capillary formation after RAE treatment. It was shown that RAE enhances vascular endothelial growth factor (VEGF) mRNA expression, and that a specific blocker of VEGF receptor 2 (KDR/Flk) inhibited the RAE-induced HUVEC proliferation. In addition, a decrease in the RAE-induced HUVEC proliferation was observed after treatment with inhibitors of phosphatidylinositol 3-kinase (PI3K), Akt and endothelial nitric oxide synthase (eNOS). Taken together, these data suggest that RAE is a potent stimulator of angiogenesis and that its pro-angiogenic effects involve the VEGF-KDR/Flk and PI3K-Akt-eNOS pathways. Copyright © 2009 John Wiley & Sons, Ltd. [source] Apoptosis of BGC823 cell line induced by p -hydroxymethoxybenzobijuglone, a novel compound from Juglans mandshuricaPHYTOTHERAPY RESEARCH, Issue 4 2009ZhiBo Li Abstract p -Hydroxymethoxybenzobijuglone (HMBBJ), a new quinone compound isolated from Juglans mandshurica (by bioassay-guided fractionation), showed cytotoxic activity in the gastric carcinoma cell line BGC823. The growth of BGC823 cells was inhibited as demonstrated by MTT assay and several cellular characteristic changes, such as cell shrinkage, chromatin condensation and apoptotic body formation with programmed cell death. Flow cytometry analysis revealed that the BGC823 cell cycle was arrested at G2/M phase by HMBBJ, and the apoptotic rate of BGC823 cells increased with respect to HMBBJ in a dose-dependent manner. HMBBJ also activated caspase-3, decreased the expression of Bcl-2 and caused a decrease in the mitochondrial membrane potential (,,m). These findings suggest that HMBBJ could significantly induce apoptosis in BGC823 cells and should be considered as a potential candidate for a chemotherapeutic drug against cancer. Copyright © 2008 John Wiley & Sons, Ltd. [source] Suppressive effect of inducible nitric oxide synthase (iNOS) expression by the methanol extract of Actinodaphne lancifoliaPHYTOTHERAPY RESEARCH, Issue 10 2004Youngleem Kim Abstract Nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) has played a crucial role in various pathophysiological processes including in,ammation and carcinogenesis. Therefore, the inhibitors of NO synthesis or iNOS gene expression have been considered as potential anti-in,ammatory and cancer chemopreventive agents. In our continuous search for iNOS inhibitors from natural products we have evaluated indigenous Korean plant extracts using an assay for inhibition of nitric oxide formation on lipopolysaccharide (LPS)-activated mouse macrophage RAW 264.7 cells. As a result, the methanolic stem extract of Actinodaphne lancifolia showed an inhibitory activity of NO production in a dose-dependent manner (IC50 = 2.5 µg/ml). Additional study demonstrated that the extract of Actinodaphne lancifolia signi,cantly suppressed the iNOS protein and gene expression in a dose-dependent manner. These results suggest that Actinodaphne lancifolia could be a potential candidate for developing an iNOS inhibitor from natural products. Further elucidation of active principles for development of new cancer chemopreventive and/or anti-in,ammatory agents could be warranted. Copyright © 2004 John Wiley & Sons, Ltd. [source] Plasma Polymer Surfaces Compatible with a CMOS Process for Direct Covalent Enzyme ImmobilizationPLASMA PROCESSES AND POLYMERS, Issue 1 2009Yongbai Yin Abstract Plasma polymerized surfaces, prepared using a CMOS compatible plasma enhanced chemical vapor polymerization technique, are found to covalently immobilize enzymes without the need for intermediate chemical linker groups. The polymerized surfaces are smooth, strongly adherent to substrates, and have a long shelf life for storage. After incubation with enzymes, a densely packed monolayer is attached. We report the effects of both oxygen etching and annealing post-processing showing that they can be implemented so as not to affect the enzyme binding performance. The fully compatible polymerization method with CMOS device manufacture processes is a potential candidate for integration into nano-CMOS biochemical sensors for direct immobilization of enzymes. [source] Synthesis, characterization, mechanical properties and biocompatibility of interpenetrating polymer network,super-porous hydrogel containing sodium alginatePOLYMER INTERNATIONAL, Issue 12 2007Lichen Yin Abstract In this investigation an interpenetrating polymer network,superporous hydrogel containing sodium alginate (IPN-SPHAlg) was synthesized. The morphology of the polymer was characterized using scanning electron microscopy, light images and porosity, and the polymer was further examined by swelling ratio, mechanical strength and biocompatibility. The results indicated that the IPN-SPHAlg possessed both large numbers of interconnected pores and an interpenetrating network. The swelling ratio of IPN-SPHAlg was lower than that of the superporous hydrogel (SPH) and it decreased as the sodium alginate/monomer ratio increased. The IPN-SPHAlg exhibited pH responsiveness and salt-sensitive properties. Compared to SPH and SPH composites, the mechanical strength of IPN-SPHAlg was significantly enhanced. Thiazolyl blue assay on AD293 cells, in situ lactate dehydrogenase assay and morphological study of rat intestine showed that the polymer induced no significant cell or mucosal damage. The fast swelling, good mechanical properties, pH sensitivity and biocompatibility of the IPN-SPHAlg suggested it as a potential candidate in the field of drug-delivery systems. Copyright © 2007 Society of Chemical Industry [source] Preparation and properties of a novel high-performance resin system with low injection temperature for resin transfer mouldingPOLYMER INTERNATIONAL, Issue 9 2004Dr Aijuan Gu Abstract A novel high-performance resin system with low injection temperature for resin transfer moulding, M4506, was developed, which was made of 4,4,-bismaleimidodiphenylmethane, o,o,-diallyl bisphenol A, o,o,-diallyl bisphenol A ether, and 1,1,-bis(4-cyanatophenyl)ethane. The processing characteristics, thermal and mechanical properties of the system were studied, and the effect of differing stoichiometries of each component on the processing and performance parameters was discussed. Investigations show that the processing properties of the M4506 system are greatly dependent on the stoichiometries of each component in the formulations, while all the three formulations developed in this paper have good processing characteristics, their suitable injection temperature are between 40 and 50 °C, depending on their respective formulation. The three formulations exhibited outstanding heat resistance (Tg = 294,300 °C) and thermal stability, good toughness and high strength, evidence that the M4506 system is a potential candidate as a high-performance RTM matrix for advance composites as well as high-performance paints with no solvents. Copyright © 2004 Society of Chemical Industry [source] Metallocene based polyolefin: a potential candidate for the replacement of flexible poly (vinyl chloride) in the medical fieldPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 9 2010M. C. Sunny Abstract A comparative assessment of the performance properties of metallocene polyolefin (m-PO) with those of plasticized poly (vinyl chloride) (pPVC) and ethylene vinyl acetate (EVA) copolymer having 18% vinyl acetate content (EVA-18), the two common polymers used for flexible medical products, is carried out. The preliminary evaluation of the processability, mechanical properties, and thermal stability of the new material, m-PO is described. The processability parameters like mixing torque and melt viscosity of m-PO are found to be comparable with those of pPVC and EVA-18. Mechanical properties such as tensile strength, elongation at break, and tear strength (TS) of m-PO are much higher than that of pPVC and EVA-18. Thermo gravimetric analysis (TGA) indicates that the thermal degradation of m-PO takes place only at temperatures above 340°C and can be processed at 170°C without much damage. Oxygen and carbon dioxide permeabilities of m-PO at three different temperatures (10, 25, and 40°C) are evaluated and compared with those of pPVC and EVA-18. It could be seen that the permeabilities of both the gases for m-PO at three temperatures were lower than those of pPVC and EVA. Biological evaluation of m-PO is carried out by assessing its cytotoxicity, hemolytic property, and blood clotting initiation. The cytotoxicity studies indicate that m-PO is non-toxic to the monolayer of L929 mammalian fibroblast cell lines on direct contact or the exposure of its extract. Non-hemolytic property of m-PO by direct contact as well as test on extract is revealed both in static and in dynamic conditions. Blood clotting time experiments indicate that the initiation of blood clotting due to m-PO is faster than that of pPVC and EVA-18. Copyright © 2009 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||