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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.
1

First principle study of Ti-Al and Pt-Ti alloys

Mahlangu, Rosinah January 2009 (has links)
Thesis (M.Sc (Physics)) --University of Limpopo, Turfloop Campus, 2009 / The structural and energetic properties of the Ti-Al and Pt-Ti alloys have been carried out using first-principles total energy calculation of the density functional theory. We found a good correlation between VASP and CASTEP calculations with the experimental data. The equilibrium lattice constants for both systems are in good agreement with the experimental values (within 3% agreement). Furthermore, the heats of formation were calculated in order to determine the relative structural stabilities of the Ti-Al and Pt-Ti alloys. We predict that the L10 TiAl is the most stable structure with the lowest heats of formation (more negative Hf) consistent with the experimental observations. The 50% composition of the PtTi SMA’s in particular B19/B19′ phases predict values to be closer to each other, with B19′ being the most stable phase. A comparison of the energy differences between different PtTi phases, yields the relative energies in the order B2>L10>B19>B19'. The elastic constants for B19/B19′ and L10 show the positive shear modulus while a negative shear modulus was observed for B2 phase (mechanical instability). Similarly, the phonon dispersions and the density of states for the B2, L10, B19 and B19′ PtTi shape memory alloys were calculated and are consistent with the heats of formation. The phonon dispersion curves revealed a softening of modes along high symmetry directions (M and R). This confirms that the B2 structure is less stable as compared to the other structures. The density of states for the 50% PtTi composition structures were also calculated and are consistent with the stability trend. Furthermore the transformation from B2-L10 was investigated using Bain’s path and the B2 and L10 phases were depicted at c/a=1 and c/a=√2 respectively. / NRF & CSIR
2

Identificação e hierarquia dos fatores que influenciam o preço do transporte rodoviário de carga / Identification and hierarchy of factors affecting the price of road freight transport

Machado, Susan Cariny Carvalho 15 June 2016 (has links)
Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2016. / Submitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2016-08-12T20:21:11Z No. of bitstreams: 1 2016_SusanCarinyCarvalhoMachado.pdf: 2806037 bytes, checksum: 6367792a7fb45e212972446b0de4a3e7 (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2016-10-20T18:48:48Z (GMT) No. of bitstreams: 1 2016_SusanCarinyCarvalhoMachado.pdf: 2806037 bytes, checksum: 6367792a7fb45e212972446b0de4a3e7 (MD5) / Made available in DSpace on 2016-10-20T18:48:48Z (GMT). No. of bitstreams: 1 2016_SusanCarinyCarvalhoMachado.pdf: 2806037 bytes, checksum: 6367792a7fb45e212972446b0de4a3e7 (MD5) / No Brasil, o mercado de transporte rodoviário de cargas (TRC) é responsável pela circulação de diversos produtos e o seu preço, diferentemente do transporte público de passageiros, não sofre controle governamental. O preço do frete é organizado e calculado individualmente por cada empresa e, por este motivo, estão ligadas às particularidades dos gastos de cada tipo de serviço. Porém, existe um conjunto de fatores que influenciam na definição do preço do frete, sendo então fundamental que as empresas tenham conhecimento e precisão das informações que implicam na situação real dos custos do serviço ofertado para que possa operar com eficiência e compreender o funcionamento do sistema de transporte de carga. O procedimento adotado parte de um aprofundamento teórico quanto aos fatores que influenciam o preço do frete e posterior aplicação de técnica de análise multicritério, por meio do Método de Análise Hierárquica (MAH), permitindo conhecer o grau de importância de tais fatores em diferentes mercados de transporte rodoviário de carga. Os resultados obtidos após esse procedimento mostram que, apesar do conhecimento das informações sobre os custos do serviço ofertado ser fundamental para que as transportadoras possam otimizar os seus resultados, é essencial para seu crescimento e sua permanência no mercado de TRC a análise de outros fatores que influenciam o preço do frete, como por exemplo, volume, tipo de carga, forma de acondicionamento, redespacho, pedágio, região, concorrência e carga de retorno, que apresentaram índices altos de importância relativa dentre os entrevistados neste estudo. _________________________________________________________________________________________________ ABSTRACT / In Brazil, the road freight transport (RFT) market is responsible for the movement of various products and their prices, differently from the public passenger transport, it does not suffer control from government. The price of freight is organized and calculated individually for each company and, therefore, are linked to the particularities of the costs for each type of service. However, there are a number of factors that influence the shipping price, and so important companies keep aware and accuracy of information that imply the actual situation of the offered service costs so that it can operate efficiently and understand the functioning of the system cargo transportation. The procedure adopted part of a theoretical study about the factors that influence the price of shipping and subsequent application of multi-criteria analysis technique, through the Analytic Hierarchy Process (AHP), allowing know the degree of importance of these factors in different road freight transport markets. The research part of a theoretical study about the factors that influence the price of shipping and subsequent application of multi-criteria analysis techniques, thus, to know the order of importance of these factors in different road freight transport markets. The results obtained after the procedure shows that, despite the knowledge of the information on service costs offered be crucial for carriers to optimize their results, it is essential for their growth and their stay in the RFT market load the analysis other factors influence the price of shipping, such as volume, type of cargo, form of packaging, re-dispatch, toll, region, competition and return cargo, which showed high levels of relative importance among respondents in this study.
3

Heterogenní radikálová modifikace polypropylenu / Heterogeneous Radical Modification of Polypropylene

Brňák, Matúš January 2018 (has links)
The diploma thesis deals with the heterogeneous technique of preparation of grafted polypropylene g maleic anhydride (PP-g-MAH). The knowledge of the course of the reaction and its impact on the PP grafting process are summarized in the theoretical part. The preparation of the grafted PP was carried out in a fluidized polymerization reactor at 115 °C, speed of mixing 210 rpm, reaction time 60 min and pressure 6 bar. The amount of grafted MAH was monitored by using a MAH concentration 3 and 5 wt% and an initiator concentration 0.25; 0.5; 1; and 1.5 wt%. Modification efficiency was compared by using 3 types of PP with different particle morphology and specific surface area. By creating the theoretical model, the maximum surface concentration of MAH was calculated and compared with experimental data. Characterization of PP materials was performed by Electron Scanning Microscopy (SEM), Differential Scanning Calorimetry (DSC) and particle surface analysis by BET. Quantitative analysis of grafted MAH was determined by FTIR spectroscopy and acid-base titration.
4

Maleic anhydride grafted polypropylene coatings on steel: Adhesion and wear.

Mahendrakar, Sridhar 05 1900 (has links)
Polymeric coatings are being used in a growing number of applications, contributing to protection against weather conditions and localized corrosion, reducing the friction and erosion wear on the substrate. In this study, various polypropylene (PP) coatings were applied onto steel substrates by compression molding. Chemical modification of PP has been performed to increase its adhesion to metallic surfaces by grafting of maleic anhydride (MAH) onto PP in the presence of dicumyl peroxide (DCP). Influence of different concentrations of MAH and DCP on the properties of resulting materials have been examined. The coated steel samples are characterized by scanning electron microscopy (SEM), shear adhesion testing, FTIR and tribometry. The coatings with 3 wt. % MAH have shown the maximum adhesion strength due to maximum amount of grafting. The wear rates increased with increasing the amount of MAH due to simultaneous increase in un-reacted MAH.
5

Regulation of Tyrosine Hydroxylase Expression by Hypoxia: Study of O2-Sensitive Rat Adrenal Chromaffin MAH Cell Line

Liu, Jingjing 10 1900 (has links)
<p> Reduced oxygen tension (i.e. hypoxia) regulates gene expression in various chromaffin cell types that synthesize catecholamines. In this study, the effect of chronic hypoxia on tyrosine hydroxylase (TH) mRNA and protein expression was investigated in the adrenomedullary chromaffin MAH cell line. RT-PCR results indicated that TH mRNA was expressed in MAH cells both during normoxia (20% 0 2) and hypoxia (5% 02). However, TH mRNA expression during chronic hypoxia was significantly higher than that during normoxia, increasing by approximately 2- fold after 16 hour exposure to chronic hypoxia. Western Blot analysis of the regulation of TH gene expression by chronic hypoxia indicated that TH protein initially decreased during 10 hr exposure to hypoxia and this was followed by a rapid increase in expression over the next 10 hr, and then by a slower increase (up to 1.3x initial control) after 72 hr exposure. Therefore, TH mRNA and protein levels were changed in MAH cells by hypoxia in a time-dependent manner. Surprisingly, cobalt treatment of MAH cells, expected to mimic the effects of chronic hypoxia, had little effect on TH gene expression. Interestingly, the decrease in TH expression protein after 10 hr exposure to hypoxia was prevented by nifedipine, an L-type calcium channel blocker. These results suggest that MAH cells represent a useful model system for examining hypoxia-induced gene regulation in an 02-sensitive cell line. Additionally, preliminary studies on HIF-1a expression in MAH cells showed that HIF-la mRNA was expressed and remained stable under both hypoxic and normoxic conditions. </p> / Thesis / Master of Science (MSc)
6

Prevalência de sintomas urinários em indivíduos portadores do Vírus Linfotrópico de Células T Humanas do tipo 1 (HTVL-1)

CONSTANTE, Caroline Santos January 2014 (has links)
Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-10-17T12:31:32Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_PrevalenciaSintomasUrinarios.pdf: 1491704 bytes, checksum: f7067ef3fc571e872068dcb65c7d4bf9 (MD5) / Approved for entry into archive by Irvana Coutinho (irvana@ufpa.br) on 2017-10-24T14:57:15Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_PrevalenciaSintomasUrinarios.pdf: 1491704 bytes, checksum: f7067ef3fc571e872068dcb65c7d4bf9 (MD5) / Made available in DSpace on 2017-10-24T14:57:16Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_PrevalenciaSintomasUrinarios.pdf: 1491704 bytes, checksum: f7067ef3fc571e872068dcb65c7d4bf9 (MD5) Previous issue date: 2014 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O vírus linfotrópico de células T humanas do tipo 1 (HTLV-1) infecta cerca de 20 milhões de pessoas em todo mundo. Ele está associado principalmente à leucemia/linfoma de células T do adulto (LLTA) e à doença neurológica paraparesia espástica tropical/mielopatia associada ao HTLV (PET/MAH). A PET/MAH provoca alterações motoras, fraqueza, rigidez nos membros inferiores, disfunções erétil e urinária. Alguns estudos demonstram que existe uma tendência de pacientes portadores de HTLV-1 apresentarem algum sintoma urinário não apenas em indivíduos com PET/MAH, mas também em indivíduos considerados como portadores assintomáticos, destacando a importância de estudos que abordem o universo dos sintomas urinários em indivíduos portadores de HTLV-1 a fim de aprofundar o conhecimento científico da evolução clínica dos indivíduos infectados pelo vírus, favorecer diagnósticos e intervenções mais precoces e melhorar a qualidade de vida e a saúde dos portadores de HTLV-1. A presente pesquisa teve por objetivo principal verificar a prevalência de sintomas urinários entre indivíduos portadores de HTLV-1 e, como objetivos específicos, descrever as características sócio-demográficas; identificar os sintomas urinários mais frequentes; verificar a associação da presença de sintomas urinários aos achados clínico-neurológicos e analisar o impacto na qualidade de vida dos sintomas urinários em indivíduos portadores de HTLV-1. Foi realizado um estudo transversal envolvendo 45 indivíduos portadores de HTLV-1 atendidos no ambulatório do NMT⁄UFPA, por meio de avaliação clínico-neurológica, avaliação quanto à presença de sintomas urinários e avaliação do impacto dos sintomas urinários sobre a qualidade de vida com a aplicação do King´s Health Questionnaire. A amostra apresentou média de 48,82 anos de idade, sendo a maioria assintomática (64,44%); do gênero feminino (64,44%); casada (64,44%), com ensino fundamental (53,33%); sem conhecimento do seu modo de infecção (53,33%). A prevalência de sintomas urinários foi de 73,33% sendo 69% entre portadores de HTVL-1 assintomáticos e 81,3% entre indivíduos com PET⁄MAH. Os sintomas urinários mais frequentes foram a noctúria (71,11%); urge-incontinência (44,44%) e urgência urinária (42,22%). Não houve associação entre os achados clínico-neurológicos e a presença de sintomas urinários e, a avaliação da qualidade de vida mostrou impacto negativo em sete dos nove domínios abordados pelo questionário. Foi encontrada alta prevalência de sintomas urinários em indivíduos portadores de HLTV-1, não somente em indivíduos com PET⁄MAH, mas também em portadores considerados assintomáticos. Sugere-a realização de novos estudos com amostras maiores e com exames de diagnóstico mais precisos para esclarecer melhor o surgimento desses sintomas entre os portadores assintomáticos do HTLV-1 e sua relação com o agravamento da mielopatia. / The human T-cells lymphotropic virus type 1 (HTLV-I) infects approximately 20 million people worldwide. It is mainly associated with adult T-cell leukemia/lymphoma (ATLL) and a neurological disease HLTV associated myelopathy/ tropical spastic paraparesis (HAM/TSP). The HAM/TSP causes motor abnormalities, weakness, increased tone in the lower limbs, urinary and erectile dysfunction. Studies show that there is a tendency of patients with HTLV-I to have some urinary symptoms. These symptoms persist not only in individuals with HAM/TSP, but also in individuals considered as asymptomatic carriers. This highlights the importance of studies that address the multitude of urinary symptoms in individuals with HTLV-I in order to deepen the scientific knowledge of the clinical progression of HTLV-I infected individuals, facilitate diagnosis, allow for earlier interventions and improve the quality of life and health of patients with HTLV-I. This research was aimed to determine the prevalence of urinary symptoms among individuals with HTLV-I with the specific objectives to describe the socio-demographic characteristics; identify the most frequent urinary symptoms reported; verify the association of the presence of urinary symptoms to neurological findings and analyze the impact on quality of life of urinary symptoms in individuals with HTLV-I. The study involved cross-sectional analysis involving 45 individuals with HTLV-I through the outpatient clinic at the NMT/UFPA. Through clinical neurological evaluation, the presence of urinary symptoms and impact assessment of urinary symptoms on quality of life by carriers HTLV-I was assessed applying the King's Health Questionnaire. The sample have had an average of 48.82 years of age, most were asymptomatic (64,44%), female (64,44%), married (64,44%), with primary education (53,33%) and without knowledge of its mode of infection (53,33%). The prevalence of urinary symptoms was 73,33% being 69% among patients with asymptomatic HTVL-I and 81,3% among individuals with HAM/TSP. The most common urinary symptoms were nocturia (71.11%), urinary urgency with incontinence (44.44%) and urinary urgency (42.22%). There was no association between neurological findings and the presence of urinary symptoms and the assessment of quality of life showed negative impact on seven of the nine areas covered by the questionnaire. High prevalence of urinary symptoms was found in individuals with HTLV-I, not only in individuals with HAM/TSP, but also in patients considered asymptomatic carriers. It is suggested that further studies with larger sample sizes and more accurate diagnostic tests to clarify development of these symptoms among asymptomatic carriers and its relationship with the worsening of myelopathy.
7

Estudo da função tímica em portadores de HTLV-1 com PET/MAH

GOMES, Jéssica Antonia Nunes January 2017 (has links)
Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-10-18T12:59:24Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EstudoFuncaoTimica.pdf: 1549137 bytes, checksum: b42257328d96b7bfbaca2684aaff57e6 (MD5) / Approved for entry into archive by Irvana Coutinho (irvana@ufpa.br) on 2017-11-07T12:47:28Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EstudoFuncaoTimica.pdf: 1549137 bytes, checksum: b42257328d96b7bfbaca2684aaff57e6 (MD5) / Made available in DSpace on 2017-11-07T12:47:28Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EstudoFuncaoTimica.pdf: 1549137 bytes, checksum: b42257328d96b7bfbaca2684aaff57e6 (MD5) Previous issue date: 2017 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Dos portadores de HTLV-1, 90% permanecem assintomáticos, 2-3% desenvolvem Leucemia Linfoma de Células T do Adulto (LLcTA) e 0,25-4% desenvolvem Paraparesia Espástica Tropical/ Mielopatia Associada ao HTLV (PET/MAH). Na PET/MAH, são encontrados infiltrados de células T CD8+ específicas na medula que destroem as células T CD4+ infectadas, levando a uma resposta imunológica ativada crônica. As células T recém-emigradas do timo (ou células T naïve) possuem círculos excisados pelo rearranjo do gene do receptor de células T (TREC) que não duplicam na proliferação celular, sendo um bom indicador para quantificar o número de células T naïve e assim avaliar a função tímica. O presente estudo almejou Verificar a função tímica de pacientes portadores da infecção pelo vírus HTLV-1 através da quantificação do número de TREC em células mononucleares do sangue periférico. Trata-se de um estudo transversal analítico, realizado com 39 pacientes, acima de 18 anos, divididos em dois grupos: com PET/MAH (PET) e sem PET/MAH (NPET). Foi realizada avaliação clínica e fisioterapêutica, coleta de sangue, separação das células linfomononucleares, extração de DNA e RNA, curva absoluta de TREC, quantificação de DNA e RNA, detecção e quantificação de partículas TREC, síntese de cDNA, expressão gênica da citocina IL-7 e análise estatística com os testes de Mann-Whitney e correlação de Spearman, com o valor de p ≤ 0,05 como nível de significância. Dos 39 pacientes estudados, dois foram excluídos do estudo por apresentarem doença autoimune. Quanto à comparação entre grupos da quantificação de TREC: há diferença entre o grupo PET e NPET (p = 0,01), nos pacientes com idade ≤59 anos entre os grupos PET e NPET (p = 0,04), nas pacientes do sexo feminino entre o grupo PET e NPET (p = 0,003) e o grupo com cadeira de rodas e sem cadeira de rodas (p = 0,05). Já com relação à comparação da expressão gênica de IL-7 entre grupos: no grupo NPET há diferença entre o grupo ≤59 anos e o ≥60 anos (p = 0,02), no sexo feminino há diferença entre o grupo PET e NPET (p = 0,04). A função tímica mostrou-se prejudicada em pacientes portadores de HTLV-1 com PET/MAH comparados àqueles sem PET/MAH, pois houve um prejuízo na produção de células T naïve nessa população, mostrada através das diferenças entre variáveis tanto no grupo PET e NPET com relação à quantificação de TREC. Apesar de ainda não estar clara a importância deste comprometimento no desencadeamento e/ou evolução da PET/MAH, infere-se que a redução da produção de células T naïve pode alterar a resposta imunológica nesses pacientes, repercutindo diretamente no quadro clínico dos mesmos. / In HTLV-1 infeccions 90% of carriers remain asymptomatic, 2-3% develop Adult T-cell leukemia/lymphoma (ATL) and 0.25-4% develop HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP). In HAM/TSP, specific CD8 + T cell infiltrates are found in the marrow that destroy infected CD4 + T cells, leading to a chronic activated immune response. Recently emigrated T cells (or naïve T cells) have excised circles by the rearrangement of T cell receptor (TREC) genes that do not double in cell proliferation, being a good indicator to quantify the number of naïve T cells and thus evaluate the thymic function. This study aimed to verify the thymic function of patients with HTLV-1 infection by quantifying the number of TREC in peripheral blood mononuclear cells. This is a cross-sectional, analytical study of 39 patients over 18 years of age, divided into two groups: HAM/TSP (PET) and without HAM/TSP (NPET). We performed a clinical and physiotherapeutic evaluation, blood collection, lymphomononuclear cell separation, DNA and RNA extraction, absolute TREC curve, DNA and RNA quantification, TREC particle detection and quantification, cDNA synthesis, cytokine IL-7 and statistical analysis with the Mann-Whitney tests and Spearman's correlation, with p ≤ 0.05 as significance level. Of the 39 patients studied, two were excluded from the study because they presented autoimmune disease. Regarding the comparison between groups of TREC quantification: there was a difference between the PET and NPET groups (p = 0.01), in patients with age ≤59 years between the PET and NPET groups (p = 0.04), in the (p = 0.003) and the group with a wheelchair and without a wheelchair (p = 0.05). As for the comparison of IL-7 gene expression between groups: in the NPET group there was a difference between the group ≤59 years and the ≥60 years (p = 0.02), in the female there was a difference between the PET and NPET groups (p = 0.04). Thymic function was impaired in patients with HTLV-1 with HAM/TSP compared to those without HAM/TSP, as there was a loss in naïve T cell production in this population, shown by the differences between variables in both PET and NPET groups With respect to the quantification of TREC. Although the importance of this compromise in the triggering and / or evolution of HAM/TSP is not yet clear, it is inferred that the reduction of naïve T cell production can alter the immunological response in these patients, directly affecting their clinical picture.
8

Padrão de resposta imunológica periférica em pacientes infectados pelo HTLV-1 e sua correlação com as manifestações neurológicas funcionais nos indivíduos com PET/MAH

DIAS, George Alberto da Silva January 2014 (has links)
Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-09-11T18:23:35Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_PadraoRespostaImunologica.pdf: 1375375 bytes, checksum: 23ce5566cb35397ecbe03996334dc56f (MD5) / Approved for entry into archive by Irvana Coutinho (irvana@ufpa.br) on 2017-09-25T18:50:25Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_PadraoRespostaImunologica.pdf: 1375375 bytes, checksum: 23ce5566cb35397ecbe03996334dc56f (MD5) / Made available in DSpace on 2017-09-25T18:50:25Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_PadraoRespostaImunologica.pdf: 1375375 bytes, checksum: 23ce5566cb35397ecbe03996334dc56f (MD5) Previous issue date: 2014 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O vírus linfotrópico de células T humanas do tipo 1 (HTLV-1) está associado principalmente a leucemia/linfoma de células T do adulto (LLcTA) e a paraparesia espástica tropical/mielopatia associado ao HTLV-1 (PET/MAH). A PET/MAH é uma doença inflamatória do sistema nervoso central (SNC), porém o mecanismo pelo qual o HTLV-1 induz a PET/MAH ainda não está totalmente esclarecido. Acredita-se que a interação vírus-hospedeiro pode levar ao desequilíbrio na resposta imunológica, com produção aumentada de citocinas inflamatórias, podendo estar relacionada ao desenvolvimento da PET/MAH. Assim, este trabalho visa analisar a resposta imunológica periférica dos pacientes portadores do HTLV-1 e correlacioná-la com as manifestações neurológicas funcionais dos pacientes com PET/MAH. Foram incluídos 69 pacientes neste estudo, sendo 43 portadores do HTLV-1 sem PET/MAH e 26 portadores do HTLV-1 com PET/MAH. Nos pacientes com PET/MAH as manifestações neurológicas funcionais avaliadas foram: força muscular, tônus muscular, equilíbrio e grau de auxílio da marcha. Cinco (05) mL de sangue foram coletados em tubo com EDTA de cada paciente e as células linfomononucleares foram separadas utilizando Ficoll-Paque. O RNA total foi extraído de 106 células utilizando o reagente Trizol. Após quantificação do RNA, 1 μg do mRNA foi submetido a transcrição reversa para obtenção do cDNA. A expressão gênica relativa das citocinas IFN-, TNF-, IL-4, IL-10 e TGF- foram realizadas através da PCR em tempo real utilizando o StepOnePlus (Applied Biosystem) com o reagente SybrGreen (Applied Biosystem). Para o cálculo da expressão gênica foi realizada através da fórmula 2-CT, onde CT é CTgene – CTgene constitutivo, sendo os genes constitutivos utilizados o GAPDH e β-actina. Os pacientes com e sem PET/MAH apresentaram predomínio de expressão gênica do perfil Th1, principalmente de IFN-. Foi observado também que nos pacientes com PET/MAH houve expressão aumentada de TNF-. O perfil Th2 (IL-4) apresentou-se diminuído, principalmente nos pacientes com PET/MAH. Quanto à resposta antiinflamatória, a expressão de IL-10 se mostrou prejudicada nos pacientes com PET/MAH e a expressão de TGF- inicialmente se mostrou elevada em ambos os grupos. Após análises da razão entre TGF-IL-10 pode-se observar que a expressão de TGF- se manteve quase que equiparada a expressão de IL-10, sugerindo a sua participação não como citocina antiinflamatória, mas como possível ação de reparação tecidual. O perfil inflamatório associou-se positivamente com o grau de auxílio na marcha e o equilíbrio, apresentando resultados significantes somente para a expressão de IFN-. Os pacientes infectados pelo HTLV-1 que desenvolvem PET/MAH apresentam aumento da resposta Th1 em relação aos pacientes que não desenvolveram PET/MAH, e esse aumento de expressão de IFN- está relacionado com o desenvolvimento e progressão da doença. / Human T-cell lymphotropic virus type 1 (HTLV-1) is associated with adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HAM/TSP is an inflammatory disease of the central nervous system (CNS); however, the mechanism by which HTLV-1 induces HAM/TSP is not yet clear. The virus–host interaction may provoke changes in the immunological response, such as the enhanced production of inflammatory cytokines, which are implicated in the pathogenesis of HAM/TSP. This work aimed to analyze the peripheral immune response of patients infected with HTLV-1 and correlate it with functional neurological manifestations in patients with HAM/TSP. In the current study, 69 HTLV-1 infected patients were studied. 26 of them developed HAM/TSP and 43 didn’t develop HAM/TSP. In patients with HAM/TSP was evaluated the functional neurological manifestations like muscle strength, muscle tone, balance and walking aid. Five mL peripheral blood was collected into a tube with EDTA and lymphomononuclear cells were separated on a Ficoll-PaqueTM Plus density gradient (GE Healthcare). Total RNA was extracted from 106 cells with Trizol reagent. After RNA quantification, 1 μg of total RNA was submitted to reverse transcription for the generation of cDNA using the Superscript III kit (Invitrogen). IFN-, TNF-, IL-4, IL-10 and TGF- gene expression was measured quantitatively with the StepOnePlus Real-Time PCR System (Applied Biosystem) using SYBR Green reagent (Applied Biosystem). The amount of mRNA in the sample was expressed as the relative amount to the GAPDH and β-actin genes, according to the formula 2-Ct, where Ct is Ctgene – Cthousekeeping gene. The gene expression showed higher expression of Th1 cytokine in patients with and without HAM/TSP, principally IFN-. In HAM/TSP patients also showed higher TNF- expression. The gene expression showed lower expression of Th2 cytokine in patients with HAM/TSP. As regards the anti-inflammatory response, gene expression of IL-10 showed impaired in patients with HAM/TSP and expression of TGF- initially showed higher in both groups. After ratio analysis between TGF-andIL it was observed that the expression of TGF-wasequivalent to the expression of IL-10, suggesting its involvement as a non-inflammatory cytokine, but as possible repair action tissue. The inflammatory profile was positively associated with the walking aid and balance, showing significant results only for the expression of IFN-. The patients infected with HTLV-1 who developed HAM/TSP showed increased Th1 response compared to patients who did not develop HAM/TSP, and this increased expression of IFN- is related to the development and progression of the disease.
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Incapacidades funcionais dos pacientes sororeativos ao HTLV com manifestações neurológicas do Núcleo de Medicina Tropical/UFPA

BARBOSA, Richelma de Fátima Miranda 23 March 2010 (has links)
Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-10-02T17:51:01Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_IncapacidadesFuncionaisPacientes.pdf: 1262231 bytes, checksum: 1a569fead1e091422b78e2209fae25ed (MD5) / Approved for entry into archive by Irvana Coutinho (irvana@ufpa.br) on 2017-10-02T18:36:11Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_IncapacidadesFuncionaisPacientes.pdf: 1262231 bytes, checksum: 1a569fead1e091422b78e2209fae25ed (MD5) / Made available in DSpace on 2017-10-02T18:36:11Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_IncapacidadesFuncionaisPacientes.pdf: 1262231 bytes, checksum: 1a569fead1e091422b78e2209fae25ed (MD5) Previous issue date: 2010-03-23 / INTRODUÇÃO: Os vírus linfotrópico humano de células T (HTLV I e II) são retrovírus que podem ocasionar manifestações neurológicas como a Paraparesia Espástica Tropical ou Mielopatia associada ao HTLV(PET/MAH). A prevalência de infecção pelo vírus é alta no Brasil (0,8 a 1,8%) principalmente na região amazônica, acometendo na sua maioria mulheres a partir dos 40 anos de idade. OBJETIVO: Descrever as incapacidades funcionais dos pacientes sororeativos ao HTLV-I com manifestações neurológicas atendidos no ambulatório do Núcleo de medicina Tropical da Universidade Federal do Pará- UFPa, em Belém-Pará. MÉTODOS: Este estudo é caracterizado como transversal composto por uma amostra de 33 pacientes sororeativos ao HTLV atendidos regularmente e cadastrados no ambulatório do Núcleo de Medicina Tropical da Universidade Federal do Pará-UFPa. Sendo 15 pacientes sororeativos ao HTLV neurológicos sintomáticos e 18 sororeativos ao HTLV assintomáticos. Foram submetidos a uma avaliação neurofuncional a respeito do relato de queixas funcionais, exame neurológico, avaliação do tônus muscular pela Escala de Ashworth Modificada e avaliação funcional pela Medida de Independência Funcional. Considerou-se um p-valor < 0,05 para o índice de significância estatística. RESULTADOS E DISCUSSÃO: Houve um predomínio de 66.6% da amostra composta por mulheres com média de idade de 51 anos bem como relevante infecção pelo HTLV do tipo I (p<0,05) nos pacientes sintomáticos e assintomáticos. Cerca de 86.7% dos pacientes sintomáticos foram diagnosticados como PET/MAH, apresentando como principais queixas funcionais a dificuldade de andar sem apoio(53.3%) e presença de dor lombar(60%) ao passo que os pacientes assintomáticos relataram fraqueza nos membros inferiores(50%) e dor lombar(44.4%). Os achados neurológicos foram Sinal de Babinski (86.7%), hiperrreflexia patelar e aquileu (73.3%). O exame do tônus muscular revelou hipertonia moderada em membros inferiores sem relevância estatística (p>0,05). As maiores médias de pontuação nos escores da Medida de Independência Funcional foram nos cuidados pessoais e mobilidade/comunicação com relevância estatística (p<0,05), as menores médias foram no Controle dos esfíncteres e Mobilidade/locomoção (p<0,05), a amostra obteve uma classificação geral de supervisão nas atividades funcionais sem haver correlação positiva com a idade dos pacientes. CONCLUSÃO: As manifestações neurológicas relacionadas à infecção por HTLV-I geram incapacidades funcionais importantes na população de pacientes sintomáticos, ao passo que os pacientes sororeativos assintomáticos estão apresentando sintomas iniciais da PET/MAH.
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Análise multivariada de características clínicas de PET/MAH e níveis de expressão gênica e derivação de modelos de predição diagnóstica em pacientes infectados com o HTLV-1

VIRGOLINO, Rodrigo Rodrigues January 2017 (has links)
Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-10-02T18:47:20Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_AnaliseMultivariadaCaracteristicas.pdf: 5198916 bytes, checksum: 0ce8e3192cf89dfe1d89945906922fa2 (MD5) / Approved for entry into archive by Irvana Coutinho (irvana@ufpa.br) on 2017-10-03T13:26:24Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_AnaliseMultivariadaCaracteristicas.pdf: 5198916 bytes, checksum: 0ce8e3192cf89dfe1d89945906922fa2 (MD5) / Made available in DSpace on 2017-10-03T13:26:24Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_AnaliseMultivariadaCaracteristicas.pdf: 5198916 bytes, checksum: 0ce8e3192cf89dfe1d89945906922fa2 (MD5) Previous issue date: 2017 / A Paraparesia Espástica Tropical/Mielopatia associada ao Vírus Linfotrópico de Células T Humanas Tipo 1 (PET/MAH) é uma condição debilitante causada pela inflamação do tecido nervoso medular, por ação do HTLV-1. Neste trabalho objetivou-se avaliar a classificação de indivíduos infectados pelo vírus e propor um modelo de predição clínica para a ocorrência de PET/MAH. Foi utilizado um banco de dados composto de 63 indivíduos infectados, sendo 23 com diagnóstico de PET/MAH pelos critérios da OMS, e variáveis preditoras funcionais (variáveis ordinais), níveis de expressão gênica (variáveis contínuas) e a variável demográfica sexo. Em um primeiro momento uma técnica de análise de componentes principais mista foi empregada, seguida de análise de conglomerados hierárquica, para investigar a associação dos indivíduos em grupos, de forma não supervisionada, e comparar com a classificação definida pelos profissionais clínicos. Em um segundo momento, foram derivados modelos de predição diagnóstica com base em regressão logística binária penalizada, a qual é adequada nos contextos de tamanho amostral reduzido. A análise não supervisionada mostrou que os pacientes se organizavam em três grupos, sendo um grupo de pacientes com PET/MAH, um grupo de pacientes sem PET/MAH e um grupo intermediário, que comporta indivíduos com e sem a doença. Na modelagem estatística foram derivados dois modelos, um com critério de penalização 0,032 e outro com critério 0,1, mais extremo, sendo ambos avaliados por validação interna usando validação cruzada de 10 vezes. As variáveis que compuseram os modelos finais foram: grau de alteração na marcha, escore de Tinetti, tônus do músculo adutor direito e esquerdo e tônus do tríceps sural esquerdo. O uso de métodos estatísticos de predição pode ser útil como ferramenta de apoio à decisão diagnóstica de PET/MAH, especialmente em contextos de recursos limitados. / Human T-cell lymphotropic virus type 1 (HTLV-1)- associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a debilitating condition resulting from inflammation of the nerve tissue of the spinal cord caused by the action of HTLV-1. The aim of the present study was to evaluate the classification of individuals infected with HTLV-1 and propose a clinical prediction model for the occurrence of HAM/TSP. A database composed of 63 infected individuals was used, 23 of whom were diagnosed with HAM/TSP using the criteria recommended by the World Health Organization. Functional predictors (ordinal variables), gene expression levels (continuous variables) and sex (demographic variable) were also used. A mixed principal component analysis was employed, followed by hierarchical cluster analysis to determine the allocation of individuals into groups in an unsupervised fashion and compare the results to the classifications defined by clinicians. Diagnostic prediction models were then derived based on penalized binary logistic regression, which is suitable when the sample size is small. The unsupervised analysis showed that the patients were arranged into three groups: patients with HAM/TSP, patients without HAM/TSP and an intermediate group composed of individuals with and without the disease. Two models were derived from the statistical modeling – one with a penalization criterion of 0.032 and another with a criterion of 0.1 (more extreme). Both models were evaluated by internal validation using 10-fold crossvalidation. The variables that composed the final models were degree of gait alteration, derived Tinetti score, left and right adductor muscle tone and left triceps surae muscle tone. Statistical prediction methods may constitute a useful tool to support the diagnoses of HAM/TSP, especially in settings with limited resources.

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