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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

625 MBIT/SEC BIT ERROR LOCATION ANALYSIS FOR INSTRUMENTATION RECORDING APPLICATIONS

Waschura, Thomas E. 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / This paper describes techniques for error location analysis used in the design and testing of high-speed instrumentation data recording and communications applications. It focuses on the differences between common bit error rate testing and new error location analysis. Examples of techniques presented include separating bit and burst error components, studying probability of burst occurrences, looking at error free interval occurrence rates as well as auto-correlating error position. Each technique contributes to a better understanding of the underlying error phenomenon and enables higher-quality digital recording and communication. Specific applications in error correction coding emulation, magnetic media error mapping and systematic error interference are discussed.
102

Detection of burst noise using the chi-squared goodness of fit test

Marwaha, Shubra 2009 August 1900 (has links)
Statistically more test samples obtained from a single chip would give a better picture of the various noise processes present. Increasing the number of samples while testing one chip would however lead to an increase in the testing time, decreasing the overall throughput. The aim of this report is to investigate the detection of non-Gaussian noise (burst noise) in a random set of data with a small number of samples. In order to determine whether a given set of noise samples has non-Gaussian noise processes present, a Chi-Squared ‘Goodness of Fit’ test on a modeled set of random data is presented. A discussion of test methodologies using a single test measurement pass as well as two passes is presented from the obtained simulation results. / text
103

STOCHASTIC DYNAMICS OF GENE TRANSCRIPTION

Xie, Yan 01 January 2011 (has links)
Gene transcription in individual living cells is inevitably a stochastic and dynamic process. Little is known about how cells and organisms learn to balance the fidelity of transcriptional control and the stochasticity of transcription dynamics. In an effort to elucidate the contribution of environmental signals to this intricate balance, a Three State Model was recently proposed, and the transcription system was assumed to transit among three different functional states randomly. In this work, we employ this model to demonstrate how the stochastic dynamics of gene transcription can be characterized by the three transition parameters. We compute the probability distribution of a zero transcript event and its conjugate, the distribution of the time durations in gene on or gene off periods, the transition frequency between system states, and the transcriptional bursting frequency. We also exemplify the mathematical results by the experimental data on prokaryotic and eukaryotic transcription. The analysis reveals that no promoters will be definitely turned on to transcribe within a finite time period, no matter how strong the induction signals are applied, and how abundant the activators are available. Although stronger extrinsic signals could enhance promoter activation rate, the promoter creates an intrinsic ceiling that no signals could cross over in a finite time. Consequently, among a large population of isogenic cells, only a portion of the cells, but not the whole population, could be induced by environmental signals to express a particular gene within a finite time period. We prove that the gene on duration follows an exponential distribution, and the gene off intervals show a local maximum that is best described by assuming two sequential exponential process. The transition frequencies are determined by a system of stochastic differential equations, or equivalently, an iterative scheme of integral operators. We prove that for each positive integer n , there associates a unique time, called the peak instant, at which the nth transcript synthesis cycle since time zero proceeds most likely. These moments constitute a time series preserving the nature order of n.
104

A candidate gene-based association study to investigate potentially adaptive genetic variation in European beech (Fagus sylvatica L.) / Eine Kandidatengen-basierte Assoziationsstudie zur Untersuchung potentiell adaptiver genetischer Variation bei der Rotbuche (Fagus sylvatica L.)

Müller, Markus 19 December 2013 (has links)
Klimawandelmodelle sagen für Deutschland sowohl höhere Jahresdurchschnittstemperaturen als auch eine Abnahme von Niederschlägen in den Sommermonaten voraus. Mögliche Konsequenzen für Bäume sind eine verlängerte Vegetationsperiode, ein erhöhtes Spätfrostrisiko und mehr Trockenstress während des Sommers. Diese veränderten Umweltbedingungen könnten zu Veränderungen der Konkurrenzverhältnisse zwischen Baumarten führen. Die Rotbuche (Fagus sylvatica L.) ist eine der wichtigsten Laubbaumarten Mitteleuropas. Daher ist das genetische Anpassungspotential dieser Baumart an den Klimawandel von großem Interesse. In dieser Studie wurden sowohl die neutrale als auch die adaptive genetische Variation der Buche untersucht. Dafür wurde ein Translokationsexperiment mit Nachkommen von Buchenpopulationen, die unter verschiedenen Umweltbedingungen in Norddeutschland wachsen, etabliert. Wiederholte Aufnahmen wichtiger phänotypischer Merkmale (Höhe, Austrieb, Trockenstresssensitivität, Sterblichkeit) zeigten signifikante Unterschiede zwischen den Populationen. Interessanterweise zeigten Populationen mit einer größeren geographischen Distanz teilweise ähnlichere Phänotypen als benachbarte Populationen. Die neutrale genetische Variation der untersuchten Sämlingspopulationen wurde anhand neun verschiedener Mikrosatellitenmarker analysiert. Zwischen den analysierten Buchenpopulationen wurde nur eine geringe genetische Differenzierung ermittelt. Die genetische Diversität war hoch und statistisch nicht signifikant unterschiedlich von den Altbeständen, aus denen sie stammten. Die hohe genetische Diversität ist eine gute Basis für Adaption, allerdings könnte sie wahrscheinlich nur eine kurzfristige Anpassung an den Klimawandel ermöglichen. Daher ist es wichtig, Einblicke in die genetische Basis von klimawandelrelevanten Merkmalen zu gewinnen. Deshalb wurden in dieser Studie Kandidatengene für das Austriebsverhalten untersucht. Bei der Analyse von Fragmenten von zehn verschiedenen Kandidatengenen wurden 20 Indels und 116 SNPs identifiziert. Insgesamt wurden 46 SNPs erfolgreich zur Genotypisierung von über 1.400 Individuen, die aufgrund ihres Austriebsverhaltens ausgewählt wurden, verwendet. Assoziationsanalysen wurden durchgeführt, um potentiell adaptive SNP-Marker zu identifizieren. Diese ergaben unter einem „generalisierten linearen Modell“ 23 signifikant mit dem Austrieb assoziierte SNPs. Ein zusätzlich verwendetes „gemischtes lineares Modell“ ergab nahezu gleiche Ergebnisse. Die phänotypische Variation, die durch signifikant mit dem Austrieb assoziierte SNPs erklärt wird, war niedrig (R2 < 2,2), aber in Übereinstimmung mit anderen Studien mit Waldbaumarten. Zusätzlich zu den Assoziationsanalysen wurden auch FST-Outlier-Analysen durchgeführt. Diese ergaben sieben verschiedene SNPs, die potentiell unter ausgleichender oder gerichteter Selektion stehen. Insgesamt wurden vier potentiell adaptive SNPs gleichzeitig durch Assoziations- und Outlier-Analysen identifiziert. Diese könnten die höchste Wahrscheinlichkeit aufweisen, an der Ausprägung des Austriebsverhaltens beteiligt zu sein. Allerdings sind viele potentiell adaptive SNPs, die in dieser Studie identifiziert wurden, nicht-kodierend oder synonym und somit nicht die kausativen SNPs, sondern eher gelinkt mit ihnen. Allerdings wurde in dieser Studie ein geringes Kopplungsungleichgewicht (linkage disequilibrium) gefunden. Somit könnten die kausativen SNPs in naher Umgebung liegen. Die in dieser Studie identifizierten potentiell adaptiven SNPs sollten in weiteren Studien mit zusätzlichen Populationen bestätigt werden.
105

Statistické zpracování družicových dat gama záblesků družice Fermi / Statistické zpracování družicových dat gama záblesků družice Fermi

Pitňa, Alexander January 2013 (has links)
Gamma-ray bursts (GRBs) are one of the phenomena that still puzzle the astrophysi- cists. Due to their extreme luminosities, they are visible in cosmological distances. They could provide a tool for understanding the early Universe. This thesis focuses on the estimation of the total energy released by the GRBs, their luminosities and how these quantities depend on the redshift. For a sample of 28 long GRBs with known redshifts, a dependence of their total energies and luminosities on the redshift is found. The thesis further studied if this dependence is either an observational bias or a real astrophysical phenomenon. Firstly, proper use of k-correction revealed that it has lit- tle effect on the redshift dependence of these quantities. Secondly, a new approach has been proposed to investigate the redshift dependence of the luminosity function. Thirdly, selection effect has been found, when investigating the sample of bursts with known redshifts, implying a caution when combining data from different sources. All these efforts show that the observational bias can still explain the redshift dependence.
106

Comparação de três diferentes suturas com fio absorvível farpado ou monofilamentar em enterorrafia em suínos

Paiva, Bruna Ribeiro January 2019 (has links)
Orientador: Juliany Gomes Quitzan / Resumo: Devido à alta incidência de cirurgias gastrointestinais nas diferentes espécies, incluindo o homem, diversas técnicas e materiais são continuamente desenvolvidos visando otimizar os procedimentos e diminuir as principais complicações observadas, dentre elas deiscência, extravasamento de conteúdo, aderências, peritonite e sepse. O fio farpado é uma recente opção de sutura, que beneficia especialmente as modalidades cirúrgicas laparoscópicas ou videoassistidas, pois a dispensabilidade de nós facilita a sutura e diminui o tempo cirúrgico. Ainda, as farpas ao redor do fio permitem melhor adesão ao tecido e distribuição uniforme da tensão. Com o objetivo de comparar três tipos suturas realizadas com o fios absorvíveis monofilamentares, farpado ou liso, em relação ao tempo de sutura, escore de aderência, resistência ao teste de ruptura e avaliação histológica, foram executadas enterorrafias em jejuno de 12 suínos (sutura farpada, sutura contínua e isolada simples). Os animais foram randomizados em três grupos (n=4), referindo-se aos dias pós-operatórios para coleta das amostras (G3, G10 e G21). Houve diferença entre as médias dos tempos de execução, quando comparadas as suturas farpada (274,33±70,48) e contínua (350,41±87,25), em relação à isolada (469,00±109,72). Comparando-se os três padrões, nos diferentes momentos, os escores de aderência e as pressões aferidas no teste de ruptura não apresentaram diferença significativa, assim como a análise histopatológica, onde não foi obser... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Due to the high incidence of gastrointestinal surgeries in many species including humans, several techniques and materials have been continuously investigated to improving the procedures towards to avoid the most common complications, including dehiscence, leakage of contents, adhesions, peritonitis and sepsis. Barbed suture has recently come under focus for laparoscopic or video-assisted procedures, once it is a knotless suture and makes the suturing time shorter. In addition, the barbs around the suture promotes better adhesion to the tissue and uniform distribution of the tension. To compare three types of sutures performed with monofilament conventional or barbed suture, both absorbable, in relation to suture time, adhesion score, burst pressure and histology, jejunal sutures were performed in 12 pigs (barbed suture, continuous suture and simple interrupted). The groups (n = 4) were randomized, referring to the postoperative days for final evaluation (G3, G10 and G21). There was a difference on suturing time, when compared barbed (274.33 ± 70.48) and continuous (350.41 ± 87.25) to the interrupted pattern (469.00 ± 109.72). Among the 3 techniques at G3, 10 or 21, adherence scores and bursting pressure were not significantly different as well as histology evaluation, since no difference could be detected, in the grade of inflammation, fibrosis, tissue alignment, necrosis and neovascularization, at the suturing sites. No complications due to suture failures were observed. Ba... (Complete abstract click electronic access below) / Mestre
107

[en] EVUATION OF TCP PERFORMANCE IN SATELLITE TRANSMISSION IN PRESENCE OF BURST ERRORS IN THE CHANNEL / [pt] AVALIAÇÃO DE DESEMPENHO DO PROTOCOLO TCP NA TRANSMISSÃO VIA SATÉLITE EM PRESENÇA DE ERROS NO CANAL

DANIEL BRODBEKIER 15 March 2004 (has links)
[pt] Este trabalho é um estudo sobre o desempenho das principais versões do protocolo TCP e de sua variação denominada STP na transmissão via satélite. Devido à grande distância da terra aos satélites geoestacionários, a transmissão via satélite se caracteriza por um grande atraso de propagação e maior ocorrência de erros em comparação com a transmissão ótica. Estes problemas causam sério impacto no desempenho do TCP pois eventuais perdas de pacote implicam em retransmissão e demorada reinicialização do protocolo. Neste estudo, abordamos especificamente o efeito dos erros no canal como fonte de perdas de pacote, considerando modelos de erros estatisticamente independentes e erros em surto. Este tipo de erro ocorre geralmente pela utilização de códigos convolucionais associados ao decodificador de Viterbi. Através de simulação em computador usando o software Matlab, foram inicialmente caracterizadas as seqüências de erros geradas por alguns codificadores convolucionais típicos. Em seguida, o efeito destas seqüências foi introduzida em simulações de uma aplicação FTP/TCP em canal satélite, comparado-se a vazão obtida com as diferentes versões do TCP. / [en] This work is a study on the performance of the main versions of protocol TCP and of its variation STP satellite transmission. Due to great distance of the land to the geostationary satellites, the satellite transmission is characterizes for a great delay of propagation and greater occurrence of errors in comparison with the optics transmission. These problems cause serious impact in the performance of the TCP therefore eventual losses of package imply in retransmission and delayed reset of the protocol. In this study, we specifically approach the effect of the errors in the canal as source of losses of package, considering models of statistically independent errors and burst errors. This type of error generally occurs for the use of convolutional code associates with Viterbi decoder. Through simulation in computer using Matlab software, we initially had been characterized the sequences of errors generated for some typical convolutional codes. After that, the effect of these sequences was introduced in simulation of an application FTP/TCP in canal satellite, compared it outflow gotten with the different versions of the TCP, using ns-2.
108

Regulação da atividade Nox2 de neutrófilos por nitróxidos/

CHAVASCO, Luciana Souza 25 February 2010 (has links)
Espécies reativas de oxigênio (ERO) produzidas por neutrófilos através do complexo Nox2 estão diretamente associadas às ações deletérias surgidas quando a inflamação escapa do controle da homeostase. A produção exacerbada destas espécies é controlada por ações de antioxidantes endógenos como a glutationa (GSH), um importante tripeptídeo redutor que repara biomoléculas oxidadas envolvidas na sinalização celular e atua como “scavenger” de bioradicais. Os nitróxidos são radicais livres, sintéticos e estáveis que apresentam propriedades antioxidantes e antiinflamatórias. Recentemente foi demonstrado que estes são capazes de modular o “burst” respiratório de macrófagos, reduzindo a produção de ânions superóxido (O2•-) gerados pelo complexo Nox2, em um mecanismo no qual atuariam como “scavengers” de radicais tiila (RS•.), alterando modificações proteicas pós-traducionais. O presente trabalho teve como objetivo avaliar a capacidade dos nitróxidos 4-9((- acridinecarbonil)-amino)-2,2,6,6-tetrametilpiperidina-1-oxil (Ac-Tempo) e 2,2,6,6- tetrametilpiperidina-1-oxil (Tempo) de interagir e indisponibilizar RS•, especialmente glutationila (GS•), modulando a produção de ERO/ERN por neutrófilos inflamatórios isolados da cavidade peritoneal. O “burst” respiratório de neutrófilos estimulados com forbol 12-miristato 13- acetato (PMA) foi monitorado através de técnicas espectrofotométricas e a capacidade de interação entre RS• e nitróxidos foi analisada através de ensaios de Ressonância Paraeletromagnética (EPR) e Espectrometria de Fluorescência. Para confirmar a produção de RS• durante a ativação do complexo Nox2, utilizou-se o agente captador de spin, 5,5- dimetilpirrolina-N-oxido (DMPO) e o sinal de EPR característico do aduto DMPO/GS• foi monitorado. Verificou-se um aumento da resposta de fluorescência, acompanhado pela redução do sinal de EPR do nitróxido em células estimuladas com PMA. Com a finalidade de verificar alterações proteicas pós-traducionais de S-glutationilação os grupos experimentais foram submetidos à técnica de “dot blotting” e o tratamento celular com o nitróxido Tempo 100 μM determinou uma diminuição do processo de S-glutationilação proteica associado à atividade do complexo Nox2. Os resultados apontam os nitróxidos como protótipos de antioxidantes e antiinflamatórios. / Reactive oxygen species (ROS), produced in neutrophils, through the Nox2 complex are directly associated with the deleterious actions that arise when inflammation escapes from the control of organic homeostasis. An exacerbated production of these species is controlled by endogenous antioxidants such as glutathione (GSH), an important tripeptide able to repair oxidized biomolecules involved in cell signaling and to act as a scavenger of bioradicals. The nitroxides are synthetic and stable free radicals which have been frequently reported because of their anti-inflammatory and antioxidant properties. Recently, it was shown that these compounds can modulate neutrophil respiratory burst, reducing the production of superoxide anion generated by the Nox2 complex in a mechanism were they act as scavenger of thiyl radicals (RS•), altering post-translational modification of proteins. The aim of this work was to evaluate the ability of nitroxides 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) and 4-(9- acridinecarbonylamino)-2,2,6,6-tetramethylpiperidine-1-oxyl (Ac-Tempo) to interact with thiyl radicals, especially glutathionyl (GS•), minimizing the production of reactive oxygen and nitrogen species by inflammatory neutrophils isolated from the peritoneal cavity of mice. The respiratory burst in neutrophils stimulated by phorbol 12-myristate 13- acetate (PMA) was monitored spectrophotometrically and the interaction between thiyl radicals and nitroxides was analyzed by Electron Paramagnetic Resonance (EPR) and Fluorescence Spectroscopy. To confirm the production of RS• during the activation of the Nox2 complex, the spin trap for GS•, 5,5-dimethylpyrroline-N-oxide (DMPO) was used and the characteristic DMPO/GS• adduct EPR signal was monitored. An increase in the fluorescence response was observed, accompanied by a reduction of EPR signal of nitroxide in cells stimulated with PMA. Posttranslational events such as S-glutathionylation were analyzed through dot blotting and the experimental groups treated with Tempo (100 μM) showed a decrease in the process of Sglutathionylation associated with the activity of the Nox2 complex. These results suggest that thiyl radicals play a role in the maintenance of the neutrophil respiratory burst and may provide a therapeutic target for inflammation management. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
109

Ativação dos neutrófilos de pacientes com lúpus eritematoso sistêmico sobre células endoteliais in vitro: implicações na lesão tecidual mediada por imunocomplexos / Activation of neutrophils from patients with systemic lupus erythematosus on endothelial cells in vitro: implications for tissue injury mediated by immune complexes

Avila, Leandro Sobrinho 15 December 2016 (has links)
O lúpus eritematoso sistêmico (LES) é uma doença autoimune e protótipo das doenças por imunocomplexos (IC). A deposição de IC em tecidos ou órgãos leva a um processo inflamatório crônico, que resulta em lesão tecidual. A fisiopatologia deste processo envolve principalmente o sistema do complemento (SC), receptores de IgG (Fc?R), neutrófilos e moléculas de adesão. Os produtos de ativação SC atraem os neutrófilos para o foco inflamatório e sua interação com os IC depositados resulta na liberação de espécies reativas de oxigênio (ERO) e das enzimas dos neutrófilos sobre os tecidos. As ERO podem levar a danos nas estruturas celulares devido ao estresse oxidativo, resultando na exposição de autoantígenos e sustentação da autoimunidade. Várias anormalidades envolvendo neutrófilos, função e expressão dos Fc?R e CR foram descritas no LES. O objetivo deste estudo foi avaliar se essas alterações podem ter implicações para o dano tecidual através do depósito de IC. Devido à importância das interações neutrófilo-endotélio-SC para a inflamação e lesão tecidual por IC no LES, este estudo propôs avaliar o efeito da ativação de neutrófilos e produtos do SC sobre as células endoteliais in vitro. Os resultados mostram que a exposição das células endoteliais aos neutrófilos/LES ativo, sem estímulo, resulta em maior peroxidação lipídica comparada com o controle espontâneo, o que não foi observado com neutrófilos/saudáveis. Contudo, na presença de IC/SHN, a peroxidação lipídica foi maior quando as células endoteliais foram expostas aos neutrófilos/LES inativo comparada ao controle espontâneo. O efeito da ativação dos neutrófilos, em todos os grupos, sobre a peroxidação lipídica das células endoteliais foi dependente da opsonização dos IC pelo complemento (IC/SHN), uma vez que não foi observado quando as proteínas do complemento foram inativadas (IC/SHI). Não houve diferença na produção de ERO entre os neutrófilos dos grupos estudados. Observou-se menor expressão dos Fc?RIIa (CD32) e CR1 em neutrófilos/LES ativo, quando comparados com o grupo controle. Houve maior liberação de catalase pelos neutrófilos/LES, quando estes foram estimulados via Fc?R, e maior produção de glutationa por neutrófilos/LES inativo quando estas células foram estimuladas via Fc?R e CR. A expressão de ICAM-1 não foi diferente entre os grupos de neutrófilos, entretanto foi menor na ausência de complemento. Não houve diferença na medida da ativação da via clássica do complemento avaliada pelo fragmento C4d. Estes resultados mostram que as células endoteliais são mais suscetíveis à peroxidação lipídica na presença de neutrófilos/LES. Contudo, quando o complemento do soro é inativado, esta suscetibilidade desaparece, bem como há menor liberação de ICAM-1 por todos os grupos de neutrófilos e maior liberação de catalase por neutrófilos/LES. A interação dos neutrófilos/LES com células endoteliais pode ser deletéria para este último e depender da atividade das proteínas do sistema complemento. O modelo desenvolvido neste estudo pode contribuir para a compreensão do envolvimento dos neutrófilos e do SC nas lesões teciduais no LES. / Systemic lupus erythematosus (SLE) is an autoimmune disease and prototype of immune complex diseases (IC). The deposition of IC in tissues or organs leads to a chronic inflammatory process, which results in tissue injury. The pathophysiology of this process mainly involves the complement system (SC), IgG (Fc?R) receptors, neutrophils and adhesion molecules. SC activation products attract neutrophils to the inflammatory focus and their interaction with deposited IC results in the release of reactive oxygen species (ROS) and neutrophil enzymes into tissues. ROS can lead to damage to cell structures due to oxidative stress, resulting in the exposure of autoantigens and the support of autoimmunity. Several abnormalities involving neutrophils, function and expression of Fc?R and CR have been described in SLE. The aim of this study was to assess whether these changes may have implications for tissue damage through the deposition of IC. Due to the importance of neutrophil-endothelial-SC interactions for inflammation and tissue damage by IC in SLE, this study proposed to evaluate the effect of the activation of neutrophils and SC products on endothelial cells in vitro. The results show that exposure of endothelial cells to active neutrophils / SLE without stimulus results in higher lipid peroxidation compared to spontaneous control, which was not observed with neutrophils / healthy. However, in the presence of IC / complement from normal human serum (NHS), lipid peroxidation was greater when endothelial cells were exposed to inactive neutrophils / SLE compared to spontaneous control. The effect of neutrophil activation in all groups on endothelial cell lipid peroxidation was dependent on IC with complement (IC / NHS), as it was not observed when complement proteins were inactivated (IC / INHS). There was no difference in ROS production among the neutrophils of the studied groups. Lower expression of Fc?RIIa (CD32) and CR1 in active neutrophils / SLE, when compared with the control group, was observed. There was greater release of catalase by neutrophils / SLE, when they were stimulated via Fc?R, and increased production of glutathione by neutrophils / inactive SLE when these cells were stimulated via Fc?R and CR. There was no difference in expression of ICAM-1 between the neutrophil groups, however it was lower in the absence of complement. There was no difference in the extent of the activation of the classical complement pathway evaluated by the C4d fragment. These results show that endothelial cells are more susceptible to lipid peroxidation in the presence of neutrophils / SLE. However, when serum complement is inactivated, this susceptibility disappears, as well as there is a lower release of ICAM-1 by all neutrophil groups and greater release of catalase by neutrophils / SLE. The interaction of neutrophils / SLE with endothelial cells may be deleterious to the latter and depends on the activity of the complement system proteins. The model developed in this study may contribute to the understanding of neutrophil and SC involvement in tissue lesions in SLE.
110

Atividade funcional de polimorfonucleares do sangue de bezerros neonatos versus Escherichia coli \"in vitro\": influência do volume de colostro mamado e da idade / Neonatal calves blood polymorphonuclear activities versus Escherichia coli \"in vitro\": colostrum volume intake and calf age influences

Bohland, Elizabeth 30 May 2008 (has links)
O objetivo foi avaliar a atividade funcional dos polimorfonucleares (PMN) do sangue de bezerros neonatos \"in vitro\" - metabolismo oxidativo induzida por: S. aureus, E. coli e PMA e fagocitose para S. aureus e E. coli, em citômetro de fluxo. Quinze animais avaliados nos tempos: t0 (antes da ingestão de colostro/leite); t1(até 48 hs. p.n); t2 (48 - 96 hs. p.n.); t3 (96 - 144 hs. p.n.); t4 (144-192 hs. p.n.); t5 (192-240 hs.p.n.) receberam quatro litros (grupo 1 - G1), dois litros de colostro ( grupo 2 - G2) e somente leite (grupo 3 - G3). O metabolismo oxidativo basal não diferiu em nenhum dos grupos e idades. Entre os grupos este foi menor em G1 do que em G3 (t3). Induzido pela S. aureus foi maior entre t1 e t3 (grupo 1), entre t2 e t3 (grupo 2) e sem diferenças (grupo 3). Entre os grupos G1 foi maior que G3 (t1). Induzido pela E.coli foi maior entre t1 e t3 (grupo 1), maior em t2 (grupo 2) e sem diferenças (grupo 3). Entre os grupos G1 foi maior que G2 e G3 (t1). O PMA estimulou a explosão respiratória em G1, G2 e G3 entre t0 e t5. Entre os grupos G1 foi menor para do que G2 e G3. A comparação entre metabolismo basal e induzido para G1 foi maior para PMA e S. aureus entre t0 e t5 e para E. coli entre t1 e t5; para G2 foi maior para o PMA entre t0 e t5, para S. aureus entre t0 e t3 e para a E. coli entre t2 e t4; para G3 foi maior para o PMA e S.aureus entre t0 e t5 e para a E. coli entre t3 e t5. A fagocitose induzida pela S. aureus foi maior nos tempos t1, t2 e t4 (grupo1) e o percentual de fagocitose foi maior após t0; para o grupo 2, foi maior em t2 e t3 e o percentual foi maior após t0; para o grupo 3, não diferiram entre os tempos. Entre os grupos G1 foi maior que G2 e G3 (t4) e o percentual foi maior para G1 e G2 (t3) do que G3 e maior para G1 do que G2 (t5). A fagocitose induzida pela E. coli e o percentual de fagocitose não diferiram em nenhum grupo. Entre os grupos G1 foi maior do que G3 (t0) e o percentual foi maior para G1 do que G2 (t2). Conclusão: o colostro não interferiu no metabolismo oxidativo basal e estimulado pelo PMA, a S. aureus estimulou o metabolismo oxidativo e a fagocitose antes e após a ingestão de colostro. A E. coli não induziu o metabolismo oxidativo (G3) e não foi eficiente para estimular a fagocitose. Não ficou esclarecida a influência da idade sobre a atividade dos PMNs. O fornecimento de quatro litros de colostro melhora resposta funcional dos PMNs para as bactérias. / The aim of this study was to evaluate \"in vitro\" functional activities of neonatal calves blood polymorphonuclear leukocytes (PMNs) - respiratory burst and phagocytosis induced by S.aureus, E.coli and PMA, measured by flow cytometry. Fifteen calves were tested at times: t0 (before milk/colostrum ingestion); t1 (until 48 hours post partum); t2 (48-96 hrs p.p.); t3 (96 - 144 hrs. p.p.); t4 (144-192 hrs. p.p.); t5 (192-240 hrs. p.p.) and the groups intakes were 4 liters of colostrum (group 1), 2 liters of colostrum (group 2) and only milk (group 3). The basal respiratory burst did not differ among groups but it was lower in G1 than G3 (t3). The burst induced by S.aureus was higher between t1 and t3 (G1) and t2 and t3 (G2) and showed no difference (G3). The G1 values were higher than G3 (t1). E.coli induced higher values between t1 and t3 (G1), higher on t2 (G2) and showed no difference (G3). Among groups G1 was higher than G2 and G3 (t1). The PMA induced the respiratory burst in G1, G2 and G3 between t0 and t5. Among groups G1 was lower in G2 than G3. The induced basal metabolism was compared and G1 was higher to PMA and S.aureus between t0 and t5 and to E.coli between t1 and t5. The G2 showed higher values to PMA between t0 and t5, to S.aureus between t0 and t3 and E.coli between t2 and t4. The G3 showed higher values in PMA and S.aureus between t0 and t5 and E.coli between t3 and t5. The S.aureus induced phagocytosis was higher on t1, t2 and t4 (G1) and the phagocystosis percentage was higher after t0. G2 groups showed higher values on t2 and t3 and higher percentage after t0. G3 had no difference on times. G1 showed higher values than G2 and G3 (t4) and G1 and G2 (t3) had higher percentage than G3 with G1 higher than G2 (t5). The E.coli induced phagocytosis and its percentage did not differ among groups. G1 was higher than G3 (t0) and G1 showed higher phagocytosis percentage than G2 (t2). Conclusion: the colostrum did not affect either, the basal respiratory burst and the one stimulated by PMA. S. aureus stimulated the respiratory burst and phagocytosis before and after the colostrum intake. E.coli did not induce the respiratory burst (G3) and did not stimulate the phagocytosis. The age influence in PMNs activity was not totally clarified. The intake of 4 litters of colostrum increases the PMNs activity against the species of bacteria studied.

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