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VARIABLE-COMPLIANCE-TYPE CONSTITUTIVE MODEL FOR METHANE HYDRATE BEARING SEDIMENTMiyazaki, Kuniyuki, Masui, Akira, Haneda, Hironori, Ogata, Yuji, Aoki, Kazuo, Yamaguchi, Tsutomu 07 1900 (has links)
In order to evaluate a methane gas productivity of methane hydrate reservoirs, it is necessary to develop a numeric simulator predicting gas production behavior. For precise assessment of long-term gas productivity, it is important to develop a mathematical model which describes mechanical behaviors of methane hydrate reservoirs in consideration of their time-dependent properties and to introduce it into the numeric simulator. In this study, based on previous experimental results of triaxial compression tests of Toyoura sand containing synthetic methane hydrate, stress-strain relationships were formulated by variable-compliance-type constitutive model. The suggested model takes into account the time-dependent property obtained from laboratory investigation that time dependency of methane hydrate bearing sediment is influenced by methane hydrate saturation and effective confining pressure. Validity of the suggested model should be verified by other laboratory experiments on time-dependent behaviors of methane hydrate bearing sediment.
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Preparatory investigations for developing a transcript-based rotavirus reverse genetics system / Luwanika MleraMlera, Luwanika January 2012 (has links)
Reverse genetics systems that are based on either viral transcripts or cDNA genome
segments cloned in plasmids have recently been reported for some of the dsRNA
viruses of the Reoviridae family, namely African horsesickness virus, bluetongue
virus and orthoreovirus. For rotaviruses, three reverse genetics systems which only
allow the manipulation of a single genome segment have been described. These
rotavirus single genome segment reverse genetics systems are not true stand-alone
systems because they require a helper virus and a recombinant virus selection step.
A true selection-free, plasmid- only or transcript-based reverse genetics system for
rotaviruses is lacking.
This study sought to identify and characterise the factors that need to be understood
and overcome for the development of a rotavirus reverse genetics system using
mRNA derived from the in vitro transcription of a consensus nucleotide sequence as
well as from double-layered particles. The consensus whole genome sequence of
the prototype rotavirus DS-1 and SA11 strains was determined using sequenceindependent
whole genome amplification and 454® pyrosequencing. For the
rotavirus DS-1 strain, a novel isoleucine in a minor population variant was found at
position 397 in a hydrophobic region of VP4. NSP1 contained seven additional
amino acids MKSLVEA at the N-terminal end due to an insertion in the consensus
nucleotide sequence of genome segment 5. The first 34 nucleotides at the 5'-
terminus and last 30 nucleotides at the 3'-terminal end of genome segment 10
(NSP4) of the DS-1 strain were determined in this study. The consensus genome
segment 11 (NSP5/6) sequence was 821 bp in length, 148 bp longer than previously
reported. The 454® pyrosequence data for a rotavirus SA11 sample with no known
passage history revealed a mixed infection with two SA11 strains. One of the strains
was a reassortant which contained genome segment 8 (NSP2) from the bovine
rotavirus O agent. The other ten consensus genome segments of the two strains
could not be differentiated. Novel minor population variants of genome segments 4
(VP4), 9 (VP7) and 10 (NSP4) were identified. Molecular clock phylogenetic
analyses of the rotavirus SA11 genomes showed that the two SA11 strains were
closely related to the original SA11-H96 strain isolated in 1958. Plasmids containing inserts of the consensus cDNA of the rotavirus DS-1 strain were
purchased and used to generate exact capped transcripts by in vitro transcription
with a T7 polymerase. Wild-type transcripts of rotavirus SA11 were obtained from in
vitro transcription using purified rotavirus SA11 double-layered particles. The purified
rotavirus DS-1 and SA11 transcripts were transfected into BSR, COS-7 and MA104
cells. Work on MA104 cells was discontinued due their very low transfection efficacy.
In BSR and COS-7 cells, rotavirus DS-1 and SA11 transcripts induced cell death.
However, no viable rotavirus was recovered following attempts to infect MA104 cells
with the BSR and COS-7 transfected cell lysates. The cell death was determined to
be due to apoptotic cell death mechanisms. Immunostaining showed that the DS-1
genome segment 6 (VP6) and SA11 transcripts were translated in transfected BSR
and COS-7 cells. Based on visual inspection, the translation seemed to be higher in
the retinoic acid-inducible gene-I (RIG-I) deficient BSR cells than in COS-7 cells.
This suggested that the transfection of rotavirus transcripts induced an innate
immune response which could lead to the development of an antiviral state.
Therefore, the innate immune response to rotavirus transcripts was investigated in
HEK 293H cells using qRT-PCR and western blot analyses. Results of this
investigation showed that RIG-I, but not MDA5 sensed rotavirus transcripts in
transfected HEK 293H cells. Furthermore, rotavirus transcripts induced high levels of
cellular mRNA encoding the cytokines IFN-1β, IFN-λ1, CXCL10 and TNF-α. Other
cytokines namely, IFN-α, IL-10, IL-12 p40 and the kinase RIP1 were not significantly
induced. Inhibiting the RNA-dependent protein kinase R (PKR) reduced the induction
of cytokines IFN-1β, IFN-λ1, CXCL10 and TNF-α, but the expression levels were not
abrogated. The importance of a consensus sequence and the insights gained in the
current study regarding the role of the innate immune response after transfection of
rotavirus transcripts into cells in culture, should aid the development of a true
rotavirus reverse genetics system. / Thesis (PhD (Biochemistry))--North-West University, Potchefstroom Campus, 2013
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Preparatory investigations for developing a transcript-based rotavirus reverse genetics system / Luwanika MleraMlera, Luwanika January 2012 (has links)
Reverse genetics systems that are based on either viral transcripts or cDNA genome
segments cloned in plasmids have recently been reported for some of the dsRNA
viruses of the Reoviridae family, namely African horsesickness virus, bluetongue
virus and orthoreovirus. For rotaviruses, three reverse genetics systems which only
allow the manipulation of a single genome segment have been described. These
rotavirus single genome segment reverse genetics systems are not true stand-alone
systems because they require a helper virus and a recombinant virus selection step.
A true selection-free, plasmid- only or transcript-based reverse genetics system for
rotaviruses is lacking.
This study sought to identify and characterise the factors that need to be understood
and overcome for the development of a rotavirus reverse genetics system using
mRNA derived from the in vitro transcription of a consensus nucleotide sequence as
well as from double-layered particles. The consensus whole genome sequence of
the prototype rotavirus DS-1 and SA11 strains was determined using sequenceindependent
whole genome amplification and 454® pyrosequencing. For the
rotavirus DS-1 strain, a novel isoleucine in a minor population variant was found at
position 397 in a hydrophobic region of VP4. NSP1 contained seven additional
amino acids MKSLVEA at the N-terminal end due to an insertion in the consensus
nucleotide sequence of genome segment 5. The first 34 nucleotides at the 5'-
terminus and last 30 nucleotides at the 3'-terminal end of genome segment 10
(NSP4) of the DS-1 strain were determined in this study. The consensus genome
segment 11 (NSP5/6) sequence was 821 bp in length, 148 bp longer than previously
reported. The 454® pyrosequence data for a rotavirus SA11 sample with no known
passage history revealed a mixed infection with two SA11 strains. One of the strains
was a reassortant which contained genome segment 8 (NSP2) from the bovine
rotavirus O agent. The other ten consensus genome segments of the two strains
could not be differentiated. Novel minor population variants of genome segments 4
(VP4), 9 (VP7) and 10 (NSP4) were identified. Molecular clock phylogenetic
analyses of the rotavirus SA11 genomes showed that the two SA11 strains were
closely related to the original SA11-H96 strain isolated in 1958. Plasmids containing inserts of the consensus cDNA of the rotavirus DS-1 strain were
purchased and used to generate exact capped transcripts by in vitro transcription
with a T7 polymerase. Wild-type transcripts of rotavirus SA11 were obtained from in
vitro transcription using purified rotavirus SA11 double-layered particles. The purified
rotavirus DS-1 and SA11 transcripts were transfected into BSR, COS-7 and MA104
cells. Work on MA104 cells was discontinued due their very low transfection efficacy.
In BSR and COS-7 cells, rotavirus DS-1 and SA11 transcripts induced cell death.
However, no viable rotavirus was recovered following attempts to infect MA104 cells
with the BSR and COS-7 transfected cell lysates. The cell death was determined to
be due to apoptotic cell death mechanisms. Immunostaining showed that the DS-1
genome segment 6 (VP6) and SA11 transcripts were translated in transfected BSR
and COS-7 cells. Based on visual inspection, the translation seemed to be higher in
the retinoic acid-inducible gene-I (RIG-I) deficient BSR cells than in COS-7 cells.
This suggested that the transfection of rotavirus transcripts induced an innate
immune response which could lead to the development of an antiviral state.
Therefore, the innate immune response to rotavirus transcripts was investigated in
HEK 293H cells using qRT-PCR and western blot analyses. Results of this
investigation showed that RIG-I, but not MDA5 sensed rotavirus transcripts in
transfected HEK 293H cells. Furthermore, rotavirus transcripts induced high levels of
cellular mRNA encoding the cytokines IFN-1β, IFN-λ1, CXCL10 and TNF-α. Other
cytokines namely, IFN-α, IL-10, IL-12 p40 and the kinase RIP1 were not significantly
induced. Inhibiting the RNA-dependent protein kinase R (PKR) reduced the induction
of cytokines IFN-1β, IFN-λ1, CXCL10 and TNF-α, but the expression levels were not
abrogated. The importance of a consensus sequence and the insights gained in the
current study regarding the role of the innate immune response after transfection of
rotavirus transcripts into cells in culture, should aid the development of a true
rotavirus reverse genetics system. / Thesis (PhD (Biochemistry))--North-West University, Potchefstroom Campus, 2013
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Strain and Sex Differences in the Hepatotoxicity of 4-Aminobiphenyl in the MouseEmami, Arian 31 December 2010 (has links)
Recent studies from our laboratory on the aromatic amine carcinogen, 4-aminobiphenyl (ABP) have shown a significantly lower prevalence of ABP-induced liver tumors in male mice lacking the N-acetyltransferases, and a dramatically lower prevalence in females than in males, but no association of tumor prevalence with strain or sex differences in levels of acute ABP-induced DNA damage. This thesis aimed to investigate the possible involvement of acute cytotoxic effects of ABP in the development of a tumor-promoting inflammatory environment. We found that wild-type male mice showed higher acute hepatotoxicity to ABP, as well as, a possible trend towards higher serum levels of the pro-inflammatory cytokine interleukin 6. This correspondence between acute ABP cytotoxicity and inflammatory response with ultimate tumor growth is consistent with a model whereby ABP not only initiates cells by damaging DNA but also promotes tumor growth in a gender-selective fashion that may be governed by gonadal hormone influences.
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Strain and Sex Differences in the Hepatotoxicity of 4-Aminobiphenyl in the MouseEmami, Arian 31 December 2010 (has links)
Recent studies from our laboratory on the aromatic amine carcinogen, 4-aminobiphenyl (ABP) have shown a significantly lower prevalence of ABP-induced liver tumors in male mice lacking the N-acetyltransferases, and a dramatically lower prevalence in females than in males, but no association of tumor prevalence with strain or sex differences in levels of acute ABP-induced DNA damage. This thesis aimed to investigate the possible involvement of acute cytotoxic effects of ABP in the development of a tumor-promoting inflammatory environment. We found that wild-type male mice showed higher acute hepatotoxicity to ABP, as well as, a possible trend towards higher serum levels of the pro-inflammatory cytokine interleukin 6. This correspondence between acute ABP cytotoxicity and inflammatory response with ultimate tumor growth is consistent with a model whereby ABP not only initiates cells by damaging DNA but also promotes tumor growth in a gender-selective fashion that may be governed by gonadal hormone influences.
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Avaliação da deformação média gerada nos intermediários e na região peri-implantar durante as etapas de confecção da prótese parcial fixa parafusada: análise com strain gauges / Evaluation of abutment and simulated bone tissue mean deformation around dental implants, during fabrication stages of screw-retained fixed partial prostheses: strain gauges analysisMax Dória Costa 30 May 2011 (has links)
A adaptação passiva e estabilidade têm se tornado os dois pré-requisitos de maior importância na escolha dos materiais e técnicas de confecção em prótese implantossuportada. A proposta deste trabalho foi avaliar, com auxílio dos strain gauges ou extensômetros lineares elétricos, a deformação média ocorrida nos intermediários e na região peri-implantar mediante a instalação da infraestrutura parafusada durante sete etapas de confecção da prótese parcial fixa. Para a investigação, foi utilizado um modelo experimental homogêneo à base de poliuretano com dois implantes hexágono externo paralelos entre si. Sobre os implantes foram acoplados pilares Multi-unit de 5 mm de altura que receberam na sua superfície três strain gauges dispostos de maneira eqüidistante entre si. Também foram colados na superfície superior do bloco experimental quatro strain gauges para cada implante, posicionados nas faces mesial, distal, vestibular e lingual visando medir as tensões nestas áreas. Os testes foram realizados parafusando os corpos de prova sobre os intermediários utilizando-se para isto um dispositivo eletrônico de torque com força máxima de 10 Ncm. As leituras foram realizadas em sete momentos, obtendo os valores médios de deformação no poliuretano e no intermediário respectivamente: 1) cilindros de cobalto-cromo pré-fabricados usinados como grupo controle (36,4µε e 87,5µε), 2) infraestrutura sobrefundida em monobloco com liga de níquel-cobalto-cromo (340,3µε e 131,4µε), 3) em seguida seccionada com espaço livre para solda (43,2µε e 66,6µε), 4) seccionada com espaço para solda preenchida com resina acrílica quimicamente ativada (Duralay) (74µε e 86,8µε), 5) seccionada e soldada (280µε e 146,2µε), 6) soldada com aplicação de cerâmica (288,7µε e 151,1µε) e 7) finalizada com aplicação do glaze, acabamento e polimento (359,9µε e 197,8µε). Estes resultados mostraram um aumento crescente da deformação média tanto nos intermediários como no poliuretano durante todas as etapas de confecção, com excessão da fundição em monobloco que atingiu altos valores, próximos da prótese finalizada. Desta forma, o procedimento de soldagem diminuiu os níveis de derformação, enquanto a aplicação da cobertura cerâmica, glaze, acabamento e polimento, aumentaram as deformações. / Passive fit and stability have become the most important prerequisites during the choice of materials and techniques to implant-supported prostheses. Therefore, the aim of this study was to verify the mean deformation in abutments and simulated bone tissue around dental implants, with the use of strain gages, during framework screw retention, analyzing seven fabrication stages of the fixed partial denture. For this research, an experimental model based on homogeneous polyurethane with two external hexagon implants parallel to each other, provided with 5 mm height multi-unit abutments. For each, abutment surface received three equidistant strain gauges and the experimental block received upper surface four strain gauges, positioned on the mesial, distal, buccal and lingual aspects. The tests were performed screwing the specimens on the abutment using an electronic torque with 10 Ncm maximum force. The readings were made in seven moments, with abutment and polyurethane mean deformation, respectively: 1) control group: cobalt-chromium prefabricated machined cylinder (36,4µε e 87,5µε), 2) framework fabricated by 1-piece method in nickel-cobalt-chromium alloy (340,3µε e 131,4µε), 3) framework sectioned with space for welding (43,2µε e 66,6µε), 4) weld space filled with chemically activated acrylic resin (Duralay) (74µε e 86,8µε), 5) framework sectioned and soldered (280µε e 146,2µε), 6) framework welded and ceramic application (288,7µε e 151,1µε) and 7) framework concluded applying glaze, finishing and polishing (359,9µε e 197,8µε). The results showed the mean strain increase in abutment and polyurethane over fabrication stages, except that framework fabricated by 1-piece method reached high values close to finished prostheses. Thus, the welding procedure decreased strain levels in simulated bone tissue around dental implants, while ceramic and glaze application, finishing and polishing procedures, increased strain.
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Avaliação da acurácia do strain pelo speckle tracking para detecção de fibrose miocárdica na ressonância magnética em portadores de doença de ChagasMacedo, Carolina Thé January 2015 (has links)
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Previous issue date: 2015 / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil / Um dos principais desafios na miocardiopatia chagásica é a detecção de
alterações precoces na função ventricular esquerda. A avaliação do strain pelo
speckle tracking na ecocardiografia bidimensional (2-D ST) é um novo método
com aplicações em diversas doenças cardíacas, tendo sido validado para
pacientes com infarto do miocárdio em comparação à ressonância magnética
cardíaca (RMC). Neste estudo, avaliamos a hipótese de que o strain global
longitudinal (SGL) possui um valor incremental à fração de ejeção (FE) pelo
método de Simpson para predição de fibrose miocárdica na RMC, em pacientes
portadores de doença de Chagas (DC). Métodos: Estudo observacional, com um
total de 58 pacientes portadores de DC. Todos os pacientes foram submetidos à
realização de ecocardiograma convencional e com strain pelo speckle tracking,
além de RMC. Resultados: A análise da curva ROC mostrou que tanto a SGL
(área sob a curva: 0,78, p = 0,001) quanto a fração de ejeção (área sob a curva:
0,82, p < 0,001) tiveram significância estatística na detecção de fibrose. Em
relação á porcentagem de fibrose, uma alta correlação foi observada tanto com a
FE pela ecocardiografia (r = - 0,70, p < 0,001) quanto com o SGL (r = 0,64, p <
0,001). Contudo, quando ajustado pela regressão linear múltipla, o SGL perdeu a
significância estatística como preditor independente de fibrose miocárdica (p =
0.111). Conclusões: SGL não possui valor incremental em relação à FE na
predição de fibrose miocárdica em pacientes portadores de DC. / One of the most challenging issues of chronic Chagas
disease is to provide earlier detection of heart involvement. Two-dimensional
speckle tracking (2-D ST) echocardiography, a new imaging modality with useful
applications in several cardiac diseases, has been validated for subjects with
myocardial infarction against cardiac magnetic resonance (CMR). Here we
hypothesize that the longitudinal global strain (LGS) has an incremental value to
ejection fraction for predicting myocardial fibrosis in subjects with Chagas disease.
Methods: This observational study comprised 58 subjects with Chagas disease,
confirmed by two positive serologic tests. All subjects underwent conventional
Doppler echocardiogram plus speckle tracking strain, and cardiac magnetic
resonance. Results: The ROC curve analysis revealed that both LGS (Area
under the curve: 0.78, p = 0.001) and ejection fraction (Area under the curve: 0.82,
p < 0.001) were significant predictors of myocardial fibrosis. Regarding the
percentage of fibrosis, a high correlation was observed with both ejection fraction
assessed by echocardiography (r = - 0.70, p < 0.001) and LGS (r = 0.64, p <
0.001). However, when adjusted through multiple linear regression, the LGS lost
statistical significance as a predictor of myocardial fibrosis (p = 0.111).
Conclusions: LGS has no incremental value to conventional ejection fraction
measurement in the prediction of myocardial fibrosis in subjects with Chagas
disease.
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Problematika hygieny pedagogického procesu na základních školách a možné zdroje školní zátěže u žáků 9.tříd / Problem of hygiene educational process in primary schools and potential sources of school strain for ninth-grade pupilsHRDINA, Jakub January 2013 (has links)
The thesis deals with hygiene of educational process and sources of school strain. Theoretical part describes learning, socialization, human needs, specifics and risk of puberty, school strain and its sources, nature of reactions to stress, issue of class climate and abuse. Part of theoretical part deals with prevention and health promotion. Two main objectives have been determined: 1. Map subjective perception of each factors of hygiene of educational process, 2. Investigate the most common sources of school strain which influences health of ninth-grade pupils. Quantitative research methods have been selected for the practical part. Data was obtained through anonymous questionnaire. The questionnaire consists of twenty questions, the first two are identifiable (gender, age) and the remaining eighteen questions are focused on fading of subjective perceptions of the factors of the educational process. Preliminary research on twenty respondents was made before the start of the survey. Collection of questionnaires was made in February and March 2013. Data were evaluated in MS Excel and the results are presented in graphical and tabular form. The research group consisted of ninth-grade pupils of primary schools in Pardubice. The sampling frame was selected by simple random sampling. Each fifteen primary schools were properly numbered and then five of them were drawn lots of a hat. In total, 300 questionnaires were distributed. Although the response rate was 100%, 68 questionnaires remained unfilled, so 232 copies (77%) was evaluated in the practical part. Of the 232 respondents,106 respondents (46%) registered male and 126 respondents (54%) enrolled female. Age of probands was between fourteen into sixteen years. The paper outlines two hypothesis: H1. The boys are satisfied with the quality of the physical factors of the educational process more than girls, H2. The girls suffer subjective health problems more often than boys. For testing of both hypothesis was selected two sample test of significance for the mean value of two sample sizes (Student´s t-test). To verify H1 was necessary to use evaluation of four closed questions related to physical factors of the educational process (illumination, noise, air quality, air temperature). Testing of H2 was mediated by data obtained from question that map frequency of health problems.Because there is no difference between the sexes in the studied phenomena, the expected hypothesis were rejected. The results of this thesis show that pupils are more dissastified with the quality of school furniture than with the quality of physical factors. Non-school breaks from teachers is a fundamental problem. More than 50% of respondents recorded this adverse effect. The issue of homework can not be ignored neither. More than 46% of pupils record having a homework every day or several times a week. Perceptions of pupils that are recorded in the results of thesis and then confronted in discussion may be used as a source of informatiion for teachers of primary schools who will be able to compare the results of the research with data obtained from their primary school.
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Caracterização microestrutural e análise de tensões residuais pelo método do furo cego em tubo de seção quadrada com costura. / Microstructural characterization and hole-drilling method applied to residual stress analisys in a seamed square tube.André de Araújo Oliveira 27 August 2015 (has links)
Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Tensões residuais são uma das principais causas de falhas em componentes
mecânicos submetidos a processos de fabricação. O objetivo do trabalho foi medir
as tensões residuais presentes em um tubo quadrado soldado por resistência
elétrica de alta frequência e caracterizar microestruturalmente o seu material. Para a
caracterização, foram utilizadas técnicas de microscopia óptica (MO), microscopia
eletrônica de varredura (MEV) e análise química quantitativa. Para a medição das
tensões residuais, foi utilizado o método do furo cego, baseado na norma ASTM
E837-08, onde rosetas (strain-gages) são coladas à peça para medir as
deformações geradas devido à usinagem de um pequeno furo no local de medição.
As deformações foram associadas às tensões residuais através de equações
baseadas na Lei de Hooke. A caracterização revelou uma microestrutura composta
basicamente de ferrita e perlita, típica de aços com baixo teor de carbono,
corroborando com a especificação fornecida pelo fabricante. As tensões residuais
encontradas foram trativas e mostraram-se elevadas, com alguns valores acima do
limite de escoamento do material. / Residual stresses are one of the main failure causes in mechanical
components submitted to manufacture process. The aim of this work was to measure
the residual stresses present in a seame welded tube welded using a high frequency
electrical resistance and to microstruturally characterize its material. Optical
microscopy (OM), scanning electron microscopy (SEM) and quantitative chemical
analysis techniques were used for the characterization. The hole-drilling method was
applied obeying the ASTM E837-08 norm to measure the residual stresses,
where strain-gages are glued to the sample to measure the deformations caused due
to the machining of a small hole in the measurement point. The deformations were
linked to the residual stresses using the Hookes Law equations. The characterization
basically showed a composite microstructure of ferrite and perlite, tipical in lowcarbon
steels, as the specification supplied by the manufacturer. The residual
stresses found were tensile and high, with some values above the material yield
strength.
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Medida do strain bidimensional do ventrículo esquerdo pré-implante percutâneo de endoprótese valvar aórtica: correlação com a evolução após o procedimento / Measurement of bidimensional strain of left ventricle before percutaneous implantation of aortic valve endoprosthesis: correlation with evolution after the procedureLucas Arraes de França 24 May 2017 (has links)
INTRODUÇÃO: O implante transcateter de prótese valvar aórtica (TAVI) surge nos dias atuais como uma opção terapêutica para os pacientes sintomáticos portadores de estenose aórtica grave. Cerca de 200 mil pacientes em todo o mundo já foram submetidos ao TAVI. Não há grandes estudos que tenham avaliado a correlação prognóstica entre parâmetros ecocardiográficos antes do TAVI e eventos cardiovasculares a longo prazo. É relevante analisar se o strain pré-procedimento e outros parâmetros se comportam como fatores preditores independentes de eventos após o procedimento. MÉTODOS: Foram avaliados, de novembro de 2009 a outubro de 2016, 86 pacientes, submetidos a avaliação ecocardiográfica antes do TAVI e 30 dias após o procedimento, com análise do strain do ventrículo esquerdo pelo speckle tracking bidimensional e outros parâmetros ecocardiográficos. Esses pacientes foram acompanhados clinicamente e avaliados quanto aos desfechos: mortalidade global, mortalidade cardiovascular, classe funcional de insuficiência cardíaca e necessidade de reinternação cardiovascular. RESULTADOS: O strain global longitudinal pré-TAVI reduzido (valor absoluto) aumentou a chance de reinternação cardiovascular (OR: 0,87; 0,77 ±0,99; P= 0,038). A redução da relação E/e´ em 30 dias após o TAVI associou-se à queda da mortalidade global (OR: 0,97; 0,95 ±0,99; P = 0,006), bem como valores elevados pré procedimento dessa relação se associaram a maiores taxas de insuficiência cardíaca classe funcional III ou IV da New York Heart Association após a intervenção (OR: 1,08; 1±1,18; P = 0,049). CONCLUSÃO: Os resultados deste trabalho indicam que o strain global longitudinal pré-procedimento demonstrou ser um preditor de reinternação cardiovascular pós-intervenção a longo prazo. A relação E/e´ pré-procedimento apresentou correlação diretamente proporcional com o desenvolvimento de insuficiência cardíaca classe funcional III ou IV a longo prazo, assim como sua queda acentuada 30 dias após o procedimento correlacionou-se com menor mortalidade global. / INTRODUCTION: Transcatheter aortic valve replacement (TAVR) is a therapeutic option for symptomatic patients with severe aortic stenosis. Approximately 200,000 patients around the world have already undergone TAVR. No large studies have evaluated prognostic correlation between echocardiographic parameters before TAVR and long-term cardiovascular events. It is relevant to analyze strain before procedure and how other parameters work as independent predictors of events after the procedure. METHODS: A total of 86 patients were evaluated from November 2009 to October 2016. They underwent echocardiographic evaluation before TAVR and 30 days after the procedure with analysis of strain of the left ventricle by bidimensional speckle tracking and other echocardiographic parameters. Patients were followed clinically and evaluated in relation to outcomes: global mortality, cardiovascular mortality, functional class of heart failure and need for cardiovascular readmissions. RESULTS: Global longitudinal strain before reduced TAVR (absolute value) increased the chance of cardiovascular readmission (odds ratio: 0.87; 0.77 ± 0.99; p = 0.038). Reduction of E/e´ relationship 30 days after TAVI was associated with a drop in global mortality (odds ratio: 0.97; 0.95 ± 0.99; p = 0.006). In addition, high values for this relation before the procedure were associated with higher rates of New York Heart Association functional class III or IV heart failure after the intervention (odds ratio: 1.08; 1.00 ± 1.18; p = 0.049). CONCLUSIONS: Results of this study indicate that global longitudinal strain before the procedure is a predictor of cardiovascular readmission after TAVR. The E/e´relationship before the procedure presented a correlation directly proportional to the development of long-term functional class III or IV heart failure as well as its accentuated drop 30 days after the procedure was correlated with lower global mortality.
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