7 research outputs found

    Myocardial tagging by Cardiovascular Magnetic Resonance: evolution of techniques--pulse sequences, analysis algorithms, and applications

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    Cardiovascular magnetic resonance (CMR) tagging has been established as an essential technique for measuring regional myocardial function. It allows quantification of local intramyocardial motion measures, e.g. strain and strain rate. The invention of CMR tagging came in the late eighties, where the technique allowed for the first time for visualizing transmural myocardial movement without having to implant physical markers. This new idea opened the door for a series of developments and improvements that continue up to the present time. Different tagging techniques are currently available that are more extensive, improved, and sophisticated than they were twenty years ago. Each of these techniques has different versions for improved resolution, signal-to-noise ratio (SNR), scan time, anatomical coverage, three-dimensional capability, and image quality. The tagging techniques covered in this article can be broadly divided into two main categories: 1) Basic techniques, which include magnetization saturation, spatial modulation of magnetization (SPAMM), delay alternating with nutations for tailored excitation (DANTE), and complementary SPAMM (CSPAMM); and 2) Advanced techniques, which include harmonic phase (HARP), displacement encoding with stimulated echoes (DENSE), and strain encoding (SENC). Although most of these techniques were developed by separate groups and evolved from different backgrounds, they are in fact closely related to each other, and they can be interpreted from more than one perspective. Some of these techniques even followed parallel paths of developments, as illustrated in the article. As each technique has its own advantages, some efforts have been made to combine different techniques together for improved image quality or composite information acquisition. In this review, different developments in pulse sequences and related image processing techniques are described along with the necessities that led to their invention, which makes this article easy to read and the covered techniques easy to follow. Major studies that applied CMR tagging for studying myocardial mechanics are also summarized. Finally, the current article includes a plethora of ideas and techniques with over 300 references that motivate the reader to think about the future of CMR tagging

    Balanço entre ácidos graxos ômega-3 e 6 na resposta inflamatória em pacientes com câncer e caquexia Omega-3 and 6 fatty acids balance in inflammatory response in patients with cancer and cachexia

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    O emagrecimento, associado à perda de massa magra, é um fenômeno observado com freqüência em pacientes com câncer. Tal condição predispõe o paciente ao maior risco de infecções, pior resposta aos tratamentos implantados e, como conseqüência, desfavorece o prognóstico de cura. Além disso, a desnutrição também está associada à pior qualidade de vida. Dessa forma, algumas terapias têm sido propostas na tentativa de reverter o catabolismo, por meio da atenuação da resposta inflamatória, observado em grande porcentagem de pacientes com câncer e caquexia. Entre elas, a suplementação com ácidos graxos da família ômega-3 pode representar uma estratégia na redução da formação de citocinas pró-inflamatórias, favorecendo a tolerância metabólica dos substratos energéticos e atenuando o catabolismo protéico, com o intuito de melhorar o prognóstico de cura de pacientes com câncer. Entretanto, os estudos mostram alguns resultados conflitantes da suplementação com ômega-3 na resposta imunológica. Por outro lado, em pacientes com câncer, os ensaios clínicos mostraram atenuar a resposta inflamatória e melhorar o estado nutricional. O objetivo deste artigo é realizar uma revisão criteriosa do assunto.<br>Emaciation and loss of lean body mass is a frequent phenomenon observed in cancer patients. This condition leads to infection risk and a poor response to treatment, thus reducing the chances of cure. Furthermore, malnutrition is also associated with a poor quality of life. Therefore, therapies have been proposed in attempt to revert the catabolism observed in most of these patients by attenuating the inflammatory response. Among them, omega-3 fatty acid supplementation may be a strategy to reduce the production of pro-inflammatory cytokines and improve metabolic substrate tolerance, decreasing protein catabolism in order to ameliorate the prognosis of cure in cancer patients. However, studies demonstrate some conflicting results of ômega-3 supplementation on immune response. On the other hand, clinical trials in cancer patients demonstrate that the inflammatory response decreases and the nutritional status improves. The aim of this paper is to elaborate a strict review of the subject

    Zellfeinbau bei Algen

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    Elimination Processes by Glands

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