3,595 research outputs found

    Cell Density Plays a Critical Role in Ex Vivo Expansion of T Cells for Adoptive Immunotherapy

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    The successful ex vivo expansion of a large numbers of T cells is a prerequisite for adoptive immunotherapy. In this study, we found that cell density had important effects on the process of expansion of T cells in vitro. Resting T cells were activated to expand at high cell density but failed to be activated at low cell density. Activated T cells (ATCs) expanded rapidly at high cell density but underwent apoptosis at low cell density. Our studies indicated that low-cell-density related ATC death is mediated by oxidative stress. Antioxidants N-acetylcysteine, catalase, and albumin suppressed elevated reactive oxygen species (ROS) levels in low-density cultures and protected ATCs from apoptosis. The viability of ATCs at low density was preserved by conditioned medium from high-density cultures of ATCs in which the autocrine survival factor was identified as catalase. We also found that costimulatory signal CD28 increases T cell activation at lower cell density, paralleled by an increase in catalase secretion. Our findings highlight the importance of cell density in T cell activation, proliferation, survival and apoptosis and support the importance of maintaining T cells at high density for their successful expansion in vitro

    Finite Element Simulation of Dense Wire Packings

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    A finite element program is presented to simulate the process of packing and coiling elastic wires in two- and three-dimensional confining cavities. The wire is represented by third order beam elements and embedded into a corotational formulation to capture the geometric nonlinearity resulting from large rotations and deformations. The hyperbolic equations of motion are integrated in time using two different integration methods from the Newmark family: an implicit iterative Newton-Raphson line search solver, and an explicit predictor-corrector scheme, both with adaptive time stepping. These two approaches reveal fundamentally different suitability for the problem of strongly self-interacting bodies found in densely packed cavities. Generalizing the spherical confinement symmetry investigated in recent studies, the packing of a wire in hard ellipsoidal cavities is simulated in the frictionless elastic limit. Evidence is given that packings in oblate spheroids and scalene ellipsoids are energetically preferred to spheres.Comment: 17 pages, 7 figures, 1 tabl

    The HARPS search for southern extra-solar planets XXXV. The interesting case of HD41248: stellar activity, no planets?

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    The search for planets orbiting metal-poor stars is of uttermost importance for our understanding of the planet formation models. However, no dedicated searches have been conducted so far for very low mass planets orbiting such objects. Only a few cases of low mass planets orbiting metal-poor stars are thus known. Amongst these, HD41248 is a metal-poor, solar-type star on which a resonant pair of super-Earth like planets has In the present paper we present a new planet search program that is using the HARPS spectrograph to search for Neptunes and Super-Earths orbiting a sample of metal-poor FGK dwarfs. We then present a detailed analysis of an additional 162 radial velocity measurements of HD41248, obtained within this program, with the goal of confirming the existence of the proposed planetary system. We analyzed the precise radial velocities, obtained with the HARPS spectrograph, together with several stellar activity diagnostics and line profile indicators. A careful analysis shows no evidence for the planetary system previously announced. One of the signals, with a period of about 25 days, is shown to be related to the rotational period of the star, and is clearly seen in some of the activity proxies. The remaining signal (P~18 days) could not be convincingly retrieved in the new data set. We discuss possible causes for the complex (evolving) signals observed in the data of HD41248, proposing that they may be explained by the appearance and disappearance of active regions on the surface of a star with strong differential rotation, or by a combination of the sparse data sampling and active region evolution.Comment: Accepted for publication in A&

    Inclusion items and financial risk assessment in systems with grazing sheep under the concentrated supplementation

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    xxxThe aim of this study was to evaluate the sensitivity and financial risk in two production systems of beef sheep, in grazing, with and without the use of concentrate, in Santa Teresa County - Espírito Santo State, Brazil. A cash flow spreadsheet was prepared. Through the sensitivity analysis it was shown that greater attention should be directed to the sale of finished animals and their acquisition. These, in descending order of relevance, followed by labor, in the system with no concentrate, and concentrated supplementation, in the system where it was present. Then, the Monte Carlo simulation was performed. Probabilities of 37.9 and 33.3% that the systems without and with the concentrate, respectively, were financially unfeasible were observed. Considering the alternative remuneration of 6%, there is a considerable risk for both options, perhaps because the proposed scenarios consider the need to implement all the infrastructure for the activity, in addition to the reduced size of the production module. The strategic use of concentrated supplement as a complement to pasture presents itself as an alternative that can reduce financial risk and increase income in intensive systems of production of beef sheep in grazing. The labor efficiency is an item that affects the financial efficiency of beef sheep production systems on pasture, especially in situations of weight gain of animals without the use of concentrated supplementation. The reduction of financial risk with the use of concentrated supplementation. Intensive grazing sheep production systems can be financially advantageous and the strategic use of concentrate can result in increased income and reduced financial risk associated with this type of production

    Endocrine disruptive action of diclofenac and caffeine on Astyanax altiparanae males (Teleostei: Characiformes: Characidae)

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    Diclofenac (DCF) and caffeine (CAF) are persistent pharmaceuticals that occur in mixtures in the aquatic ecosystems causing effects in the reproductive physiology of aquatic organisms. This study evaluated the physiological reproductive responses of Astyanax altiparanae males exposed to nominal concentrations of DCF (3.08 mg L− 1) and CAF (9.59 mg L− 1) separately and combined, for 96 h. The steroids profile, estrogenic biomarker vitellogenin (vtgA), testes and liver morphology, and also mortality of males were assessed. DCF and CAF degradation was 5% of the initial concentration for 24 h. The LC50 of the DCF and CAF were 30.8 mg L− 1 and 95.9 mg L− 1, respectively. Males exposed to DCF and CAF exhibited a reduction of 17β-Estradiol (E2) concentration compared to control (CTL). Similarly, testosterone (T) was also reduced in the DCF treatment, but this response was not observed in 11-Ketotestosterone (11-KT). Males exposed to DCF + CAF combined did not exhibit differences in T, E2 and 11-KT steroids. The vtgA gene expression and the sperm concentration did not change among the treatments. Moreover, acute exposure revealed a hypertrophy of hepatocytes cells in the DCF and DCF + CAF treatments. In conclusion, DCF and CAF, isolated, exhibit an endocrine disruptive activity in A. altiparanae male, an opposite response observed with the mixture of both compounds that abolishes the endocrine disruptive effects. DCF seems to be more toxic for this species, altering also hepatocytes morphology.Fil: Godoi, Filipe G.A.. Universidade de Sao Paulo; BrasilFil: Muñoz Peñuela, Marcela. Universidade de Sao Paulo; BrasilFil: Olio Gomes, Aline D.. Universidade de Sao Paulo; BrasilFil: Tolussi, Carlos E.. Universidade Anhembi-Morumbi; BrasilFil: Brambila Souza, Gabriela. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Branco, Giovana S.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Lo Nostro, Fabiana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Moreira, Renata. Universidade de Sao Paulo; Brasi

    The contrasting chemical reactivity of potent isoelectronic iminopyridine and azopyridine osmium(ii) arene anticancer complexes

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    A wide variety of steric and electronic features can be incorporated into transition metal coordination complexes, offering the prospect of rationally-designed therapeutic agents with novel mechanisms of action. Here we compare the chemical reactivity and anticancer activity of organometallic OsII complexes [Os(η6-arene)(XY)Z]PF6 where arene = p-cymene or biphenyl, XY = N,N′-chelated phenyliminopyridine or phenylazopyridine derivatives, and Z = Cl or I. The X-ray crystal structure of [Os(η6-p-cym)(Impy-OH)I]PF6·0.5CH2Cl2·H2O (Impy-OH = 4-[(2-pyridinylmethylene)amino]-phenol) is reported. Like the azopyridine complexes we reported recently (Dalton Trans., 2011, 40, 10553–10562), some iminopyridine complexes are also potently active towards cancer cells (nanomolar IC50 values). However we show that, unlike the azopyridine complexes, the iminopyridine complexes can undergo aquation, bind to the nucleobase guanine, and oxidize coenzyme nicotine adenine dinucleotide (NADH). We report the first detection of an Os-hydride adduct in aqueous solution by 1H NMR (−4.2 ppm). Active iminopyridine complexes induced a dramatic increase in the levels of reactive oxygen species (ROS) in A549 lung cancer cells. The anticancer activity may therefore involve interference in the redox signalling pathways in cancer cells by a novel mechanism

    Diclofenac and caffeine inhibit hepatic antioxidant enzymes in the freshwater fish Astyanax altiparanae (Teleostei: Characiformes)

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    Although concentrations of pharmaceutical compounds in aquatic ecosystems are low, they can cause toxic effects on organisms. The aim of this study was to evaluate the effects of diclofenac (DCF), a non-steroidal anti-inflammatory drug, and caffeine (CAF), a central nervous system stimulant, both alone or combined, in Astyanax altiparanae males under acute exposure (96 h), measuring neurotoxicity biomarkers, antioxidant response and damage at biochemical and cellular levels. DCF concentration in water, separated and combined, was 3.08 mg L−1 and that of CAF was 9.59 mg L−1. To assess neurotoxicity, brain and muscle acetylcholinesterase (AChE) activities were measured. To evaluate oxidative stress, the enzymatic activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione S-transferase (GST), as well as lipoperoxidation (LPO), were analyzed in liver and gills. Activity of hepatic cyclooxygenase (COX) was also evaluated. Genotoxicity was assessed in blood using comet assay and micronucleus test, as well as nuclear abnormalities. DCF and CAF, alone or combined, had neither effect on AChE activity, nor in the activity of SOD, CAT, GPx and GST in gills. In liver, DCF inhibited SOD and GPx activity, CAF inhibited CAT activity, the mixture inhibited SOD and GST activity; although only fish exposed to CAF showed increased hepatic LPO. Under these experimental conditions, no effect on COX activity was observed, nor cytotoxic and genotoxic damage. The most pronounced effects were caused by the drugs separately, since both compounds altered the enzymes, but only CAF triggered LPO, showing more harmful effects.Fil: Muñoz Peñuela, Marcela. Universidade de Sao Paulo; BrasilFil: Lo Nostro, Fabiana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Dal'Olio Gomes, Aline. Universidade de Sao Paulo; BrasilFil: Tolussi, Carlos Eduardo. Universidade Anhembi Morumbi; BrasilFil: Branco, Giovana Souza. Universidade de Sao Paulo; BrasilFil: Pinheiro, João Paulo Silva. Universidade de Sao Paulo; BrasilFil: Godoi, Filipe Guilherme Andrade de. Universidade de Sao Paulo; BrasilFil: Moreira, Renata Guimarães. Universidade de Sao Paulo; Brasi

    Terapia a laser de baixa intensidade e Calendula officinalis no reparo de úlcera em pé diabético

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    OBJETIVO Evaluar los efectos de la Terapia con Láser de Baja Intensidad aislada y asociada con el aceite de Calendula officinalis en la reparación de úlceras en pie diabético. MÉTODO Estudio de caso clínico, experimental, controlado, randomizado, prospectivo, intervencionista, de carácter cuantitativo. La muestra estuvo compuesta de 32 pacientes diabéticos, de ambos géneros. Los participantes fueron distribuidos aleatoriamente en cuatro grupos. Ecografía Doppler, evaluación del Índice Tobillo-Brazo, Inventario breve de dolor y escala visual analógica fueron realizados al inicio y después de 30 días. RESULTADOS Hubo reducción del dolor en los grupos Terapia con Láser de Baja Intensidad y Terapia con Láser de Baja intensidad asociada con los Ácidos Grasos Esenciales, con pOBJECTIVE To evaluate the effects of low-level laser therapy isolated and associated with Calendula officinalis oil in treating diabetic foot ulcers. METHOD An experimental, randomized, controlled, prospective, interventional clinical case study using a quantitative approach. The sample consisted of 32 diabetic patients of both genders. Participants were randomly divided into four groups. Doppler Ultrasound evaluation of the Ankle-Brachial Index, brief pain inventory and analog pain scale were performed at baseline and after 30 days. RESULTS Reduced pain was observed in the Low-level laser therapy and Low-level laser therapy associated with Essential Fatty Acids groups (pOBJETIVO Avaliar os efeitos da Terapia a Laser de Baixa Intensidade isolada e associada ao óleo de Calendula officinalis no reparo de úlceras em pé diabético. MÉTODO Estudo de caso clínico, experimental, controlado, randomizado, prospectivo, intervencional, de caráter quantitativo. A amostra foi composta de 32 pacientes diabéticos, de ambos os gêneros. Os participantes foram distribuídos aleatoriamente em quatro grupos. Ultrassom Doppler, avaliação do Índice Tornozelo-Braquial, Inventário breve de dor e escala de dor analógica foram realizados no início e após 30 dias. RESULTADOS Houve redução da dor nos grupos Terapia a Laser de Baixa Intensidade e Terapia a Laser de Baixa intensidade associada aos Ácidos Graxos Essenciais, com
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