154 resultados para PMN


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Innate immunity is based in pre-existing elements of the immune system that directly interact with all types of microbes leading to their destruction or growth inhibition. Several elements of this early defense mechanism act in concert to control initial pathogen growth and have profound effect on the adaptative immune response that further develops. Although most studies in paracoccidioidomycosis have been dedicated to understand cellular and humoral immune responses, innate immunity remains poorly defined. Hence, the main purpose of this review is to present and discuss some mechanisms of innate immunity developed by resistant and susceptible mice to Paracoccidioides brasiliensis infection, trying to understand how this initial host-pathogen interface interferes with the protective or deleterious adaptative immune response that will dictate disease outcome. An analysis of some mechanisms and mediators of innate immunity such as the activation of complement proteins, the microbicidal activity of natural killer cells and phagocytes, the production of inflammatory eicosanoids, cytokines, and chemokines among others, is presented trying to show the important role played by innate immunity in the host response to P. brasiliensis infection.

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For the first time, the resonance Raman spectroscopy was used to characterize polymers derived from meta- and para-nitroanilines. In order to improve the polymer structure analysis, other techniques were also used such as FTIR, UV-vis, XRD, XPS, EPR and N K-XANES. The insertion of strong electron-withdrawing groups (NO2) in polyaniline (PANI)-like backbone causes drastic changes in the lower energy charge transfer states, related to the polymer effective conjugation length. The resonance Raman data show that the NO2 moiety has a minor contribution on the CT state in poly(meta-nitroaniline), PMN, while in the poly(para-nitroaniline), PPN, the quinoid structure induced by para-substitution increases the charge density of NO2 groups, causing a more localized chromophore. The characterization of the imine nitrogen and of the protonated segments was done by XPS, N K-XANES and EPR spectroscopies and the lower polymerization degree of PPN, in comparison to PMN, is confirmed by XRD and TG data. (C) 2007 Elsevier B.V. All rights reserved.

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Acute pain is a significant problem in the postoperative setting. Patients report a lack of information about pain-control measures and ineffective pain control. Nurses continue to rely on pharmacologic measures and tend to under-administer analgesics. The purpose of this study was to determine the strategies nurses used to manage patients’ pain in the postoperative setting. It also sought to examine the effect of context, including organization of care, nurses’ prioritization of work activities, and pressures during a working shift, on their pain-management strategies. An observational design was used in two surgical units of a metropolitan teaching hospital in Melbourne, Australia. Six fixed observation times were identified as key periods for pain activities, each comprising a 2-hour duration. An observation period was examined at least 12 times, resulting in the completion of 74 observations and the identification of 316 pain cases. Fifty-two nurses were observed during their normal day’s work with postoperative patients. Six themes were identified: managing pain effectively; prioritizing pain experiences for pain management; missing pain cues for pain management; regulators and enforcers of pain management; preventing pain; and reactive management of pain. The findings highlighted the critical nature of communication between clinicians and patients and among clinicians. It also demonstrated the influence of time on management strategies and the relative importance that nurses place on nonpharmacologic measures in actual practice. This research, which portrays what happens in actual clinical practice, has facilitated the identification of new data that were not evident from other research studies.


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Unrelieved pain is a worldwide health care problem that can lead to unnecessary complications and increased health care expenditure. The aim of this study was to examine nurses' knowledge and attitudes toward pain in Saudi Arabia. A descriptive design was employed using the Nurses' Knowledge and Attitudes Survey regarding pain. The study took place in a tertiary teaching hospital in Saudi Arabia. All nurses employed in the hospital were eligible to participate. A total of 775 questionnaires were distributed to nurses working in acute care, intensive care, and nursing education and administration settings. In all, 593 respondents completed the questionnaires, representing a response rate of 76.5%. Data were analyzed using descriptive and inferential statistics. Most participants were from overseas (97.5%), speaking 23 different languages; 36.5% of nurses held a bachelors of science degree in nursing or the equivalent. The mean score of correctly answered items in was 16.9 (95% confidence interval, 16.6-17.31) out of a total possible score of 40. Nurses demonstrated some misconceived attitudes such as not giving the required dose of morphine to a smiling patient despite the patient being in pain. It is of concern that the findings identified problems of inadequate knowledge and inappropriate attitudes regarding pain assessment and management in Saudi Arabia. Considering these problems, the development of pain programs and policies affecting national and international nurses is highly imperative.

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The Iota, Kappa and Lambda commercial carrageenans are rarely pure and normally contain varying amounts of the other types of carrageenans. The exact amount of impurity depends on the seaweed source and extraction procedure. Then, different analysis methods have been applied for determination of the main constituents of carrageenans because these three carrageenans are extensively used in food, cosmetic and pharmaceutical industry. The electrophoresis of these compounds proved that the carrageenans are constituted by sulfated polysaccharides. These compounds were characterized by colorimetric methods and was observed that the Lambda carrageenan shown the greater value (33.38%) of sulfate. These polymers were examined by means of 13C NMR spectroscopy and infrared spectra. The polysaccharides consisted mainly of units alternating of sulfated galactoses and anhydrogalactoses. The aim of the study was also to test the inflammatory action of these different polysaccharides. A suitable model of inflammation is acute sterile inflammation of the rat hind limb induced by carrageenan. Paw edema was induced by injecting carrageenans (κ, ι and λ) in saline into the hind paw of a male Wistar rats (175–200 g). The pathway to acute inflammation by carrageenan (kappa, iota and lambda) were expressed as time-edema dependence and measured by paw edema volume. For this purpose, was used an apparatus (pakymeter), which makes it possible to measure the inflammation (swelling of the rat foot) with sufficient accuracy. The results showed that κ-carrageenan (1%) have an edema of 3.7 mm and the paw edema increase was time and dose dependent; the ι-carrageenan (0.2%) caused an edema of 4 mm and the λ-carrageenan (1%) caused an edema of 3.6 mm. Other model was used in this study based in the inflammation of pleura for comparatives studies. Injection of carrageenans into the pleural cavity of rat induced an acute inflammatory response characterized by fluid accumulation in the pleural cavity, a large number of neutrophils and raised NO production. The levels of NO were measured by Griess reactive. The ι-carrageenan caused the greater inflammation, because it has high concentration of nitrite/nitrate (63.478 nmoles/rat), exudato volume (1.52 ml) and PMNs (4902 x 103 cells). Quantitative evaluation of inflammations of rats is a useful and important parameter for the evaluation of the efficacy of anti-inflammatory drugs

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Investigou-se o efeito do succinato de cloranfenicol (30 mg/kg, a cada 12 h, durante 4 dias, IP) sobre o acúmulo de leucócitos polimorfonucleares (PMN) na pleurisia induzida pela carragenina (150 mig) em ratos (Wistar, machos, 180-230 g, n = 12) diabéticos (40 mg/kg de aloxana, IV). O antibiótico produziu aumento de 36% no número de PMN (p<0,05) migrados para a cavidade pleural de animais normais. O estado diabético provocou redução de 45% dos PMN (p<0,05) acumulados no exsudato pleural de animais não tratados com o antibiótico. Por outro lado, animais diabéticos tratados com succinato de cloranfenicol apresentaram resposta de PMN que não diferiu estatisticamente do observado em animais controle, não tratados. A contagem total e diferencial dos leucócitos circulantes realizada antes e 4 h depois da aplicação da carragenina não diferiu estatisticamente entre os grupos.

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Slightly < 111 >-oriented 0.65Pb(Mg1/3Nb2/3)03-0.35PbTiO(3) ceramic was prepared using fine powders obtained by means of an alternative and promising chemical oxide precursor method. High quality samples with improved structural, microstructural, dielectric and ferroelectric properties were obtained. The dielectric constant value (epsilon similar to 2577) measured at 1 kHz is compared to unpoled < 112 > grain-oriented ceramics while the remanent polarization (P-r similar to 19-1 mu cm(-2)) is compared with random grain-oriented ceramics. These results point out the viability to produce ferroelectric PMN-PT ceramics of very good quality using powder precursors prepared from this chemical method. (c) 2007 Elsevier B.V. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Ethanol-induced oxidative damage is commonly associated with the generation of reactive oxygen molecules, leading to oxidative stress. Considering that antioxidant activity is an important mechanism of action involved in cytoprotection, the aim of this work was to evaluate the antioxidant properties of the alkaloid indigo (1) (2 mg/kg, p. o.), obtained from the leaves of Indigofera truxillensis Kunth (Fabaceae), on rat gastric mucosa submitted to ethanol-induced (100%, 1 mL, p.o.) gastric ulcer. Enzymatic assays and DNA fragmentation analysis were performed. When ethanol was administered to the control group, the sulfhydryl content (SH) and the glutathione peroxidase (GPx) activity decreased by 41% and 50%, respectively; in contrast, superoxide dismutase (SOD) and glutathione reductase (GR) activities increased by 56% and 67%, respectively. Additionally, myeloperoxidase (MPO) activity, a marker for free radical generation caused by polymorphonuclear neutrophil (PMN) tissue infiltration, also increased 4.5-fold after ethanol treatment. Rat gastric mucosa exposed to ethanol showed DNA fragmentation. Indigo alkaloid pretreatment protected rats from ethanol-induced gastric lesions. This effect was determined by the ulcerative lesion area (ULA), indicating an inhibition of around 80% at 2 mg/kg. This alkaloid also diminished GPx activity, which was higher than that observed with ethanol alone. However, this effect was counterbalanced by increased GR activity. Indigo was unable to restore alterations in SOD activity promoted by ethanol. After indigo pretreatment, SH levels and MPO activity remained normal and gastric mucosa DNA damage caused by ethanol was also partially prevented by indigo. These results suggest that the gastroprotective mechanisms of indigo include non-enzymatic antioxidant effects and the inhibition of PMN infiltration which, in combination, partially protect the gastric mucosa against ethanol-induced DNA damage.

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The present work reports the effects caused by barium on phase formation, morphology and sintering of lead magnesium niobate-lead titanate (PMN-50PT). Ab initio study of 0.5PbMg(1/3)Nb(2/3)O(3)-0.5Ba(x)Pb((1-x))TiO(3) ceramic powders, with x = 0, 0.20, and 0.40 was proposed, considering that the partial substitution of lead by barium can reestablish the equilibrium of monoclinic-tetragonal phases in the system. It was verified that even for 40 mol% of barium, it was possible to obtain pyrochlore-free PMN-PT powders. The increase of the lattice parameters of PMN-PT doped-powders confirmed dopant incorporation into the perovskite phase. The presence of barium improved the reactivity of the powders, with an average particle size of 120 nm for 40 mol% of barium against 167 mn for the pure sample. Although high barium content (40 mol%) was deleterious for a dense ceramic, contents up to 20 mol% allowed 95% density when sintered at 1100 degrees C for 4 h. (c) 2007 Elsevier Ltd. All rights reserved.

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Recent interest in the annexin 1 field has come from the notion that specific G-protein-coupled receptors, members of the formyl-peptide receptor (FPR) family, appear to mediate the anti-inflammatory actions of this endogenous mediator. Administration of the annexin 1 N-terminal derived peptide Ac2-26 to mice after 25 min ischemia significantly attenuated the extent of acute myocardial injury as assessed 60 min postreperfusion. Evident at the dose of 1 mg/kg (similar to9 nmol per animal), peptide Ac2-26 cardioprotection was intact in FPR null mice. Similarly, peptide Ac2-26 inhibition of specific markers of heart injury (specifically myeloperoxidase activity, CXC chemokine KC contents, and endogenous annexin 1 protein expression) was virtually identical in heart samples collected from wild-type and FPR null mice. Mouse myocardium expressed the mRNA for FPR and the structurally related lipoxin A(4) receptor, termed ALX; thus, comparable equimolar doses of two ALX agonists (W peptide and a stable lipoxin A4 analog) exerted cardioprotection in wild-type and FPR null mice to an equal extent. Curiously, marked (>95%) blood neutropenia produced by an anti-mouse neutrophil serum did not modify the extent of acute heart injury, whereas it prevented the protection afforded by peptide Ac2-26. Thus, this study sheds light on the receptor mechanism(s) mediating annexin 1-induced cardioprotection and shows a pivotal role for ALX and circulating neutrophil, whereas it excludes any functional involvement of mouse FPR. These mechanistic data can help in developing novel therapeutics for acute cardioprotection.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Precursor solutions for Pb(Mg1/3Nb2/3)O-3 (PMN) synthesis were obtained by Pechini's method. The influence of the concentration of organic materials on the phase formation has been studied. For this purpose, PMN solutions were prepared with different precursors and were characterized by thermogravimetric and differential thermal analysis. The obtained solutions were deposited onto a Si (100) substrate by dip coating and pre-treated in a hot plate at 300 degreesC for 1 h. The films were annealed at 600, 700, 800 and 900 degreesC for 1 h and characterized by X-ray diffraction. The perovskite phase was formed after annealing at 600 and 700 degreesC when the solution of PMN was prepared with a lower amount of organic material and starting with mobium oxide. By increasing the temperature to 800 or 900 degreesC, only the formation of pyrochlore phase was observed. With the solution prepared from mobium ethoxide, only the presence of pyrochlore phase was observed independently of the annealing temperature. (C) 2002 Elsevier B.V. B.V. All rights reserved.

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Este trabalho avaliou a ação do Diclofenaco de Sódio (DS) na cicatrização de anastomoses realizados no íleo terminal de ratos, tendo sido analisados os seguintes parâmetros: evolução clínica, resistência mecânica, colágeno tecidual e alterações histopatológicas. Foram utilizados 519 ratos Wistar divididos em 4 grupos experimentais. O Grupo 1: Controle sem anastomose, 52 ratos tratados com solução fisiológica (SF)3 ml/kg de peso, administrada por via intra-muscular (IM) por 4 dias; Grupo 2: 110 ratos submetidos à anastomose no íleo terminal + SF; Grupo 3: 52 ratos tratados com DS na dose de 3 mg/kg de peso por dia, IM, por 4 dias e o Grupo 4: 295 ratos tratados com DS e submetidos à anastomose no íleo terminal, recebendo DS de maneira idêntica ao grupo anterior. Dez animais sem manipulação, foram utilizados para medidas da força de ruptura e dosagens bioquímicas, com obtenção de parâmetros caracterizados como MO. Os parâmetros foram analisados no 4o, 7o, 14o e 21o dia de pós-operatório. Os animais do Grupo 1 não apresentaram alterações clínicas durante o período de acompanhamento. No Grupo 3, 15,4% dos animais apresentaram diarréia. Neste grupo houve uma diminuição do colágeno tecidual e da força de ruptura quando comparados com o grupo 1. Entre os animais submetidos à anastomoses no íleo terminal, observou-se taxa de mortalidade maior nos animais que receberam DS, além de retardo na cicatrização, caracterizado por uma maior reação inflamatória polimorfonuclear, retardo na regeneração da mucosa, diminuição de macrófagos e do colágeno tecidual. Pelos resultados obtidos concluiu-se que o DS é deletério à evolução cicatricial de anastomoses realizadas no íleo terminal de ratos