1000 resultados para Tensión
Resumo:
The aim of this study was to investigate the use of ropivacaine combined or not with different opioids, for epidural anesthesia in bitches submitted to elective ovariosalpingohisterectomy (OSH). Thirty two mixed-breed female dogs, adults were used with medium weigh of 10.5kg. The animals were premedicated with acepromazine (0.05mg.kg-1, IM) and midazolam (0.2mg.kg-1, IM) and allocated in four experimental groups: group 1(n=8): ropivacaine: 0.3 mL.kg-1; group 2(n=8): ropivacaine + morphine (0.1 mg.kg-1); group 3(n=8): ropivacaine + butorphanol (0.1 mg.kg-1); and group 4(n=8): ropivacaine + tramadol (0.5 mg.kg-1) administered epidurally. Heart and respiratory rate; systolic arterial pressure; rectal temperature; arterial blood gas partial pressures; blood pH; sedation and muscular relaxation degree were evaluated at different experimental moments. The data were submitted to ANOVA and compared by Kruskal Wallis, Friedman, Dunn, Tukey and Chi-square test (p≤0.05). Minimum cardiorespiratory alterations were observed and the group of the ropivacaíne combined with the butorphanol (G3) presented a more cranial blockage, what allowed the accomplishment of OSH without induction in six animals (75%) whereas most of the others needed anesthetic rescue. The results allow us to conclude that the use of ropivacaine sole or combinated with morphine, butorphanol or tramadol, for epidural anesthesia, didn't promote significant cardiorrespiratory depression and the ropivacaine associated to the butorphanol allowed the accomplishment of OSH in bitches.
Resumo:
El control de los riesgos ergonómicos es parte del paquete de medidas de Buenas Prácticas de Laboratorio y Bioseguridad. De este modo, la mala postura, la iluminación o ventilación inadecuadas , prolongada jornada de trabajo, la monotonía y la actividad repetitiva, intensa rutina, el control de la productividad , el estrés y el trabajo por la noche son factores a los riesgos ergonómicos. Como se relacionan a los elementos físicos y de organización también pueden interferir con la comodidad y la salud del personal de laboratorio. Riesgos ergonómicos no sólo pueden generar trastornos psicológicos y fisiológicos que causan graves daños a la salud, sino también comprometer la productividad del laboratorio y reducir el equipo de seguridad , ya que producen cambios en el cuerpo y el estado emocional, tales como trastornos o lesiones relacionadas con el cansancio físico producido por el trabajo repetitivo, dolor muscular, alteraciones del sueño, diabetes, trastornos de los nervios , la taquicardia , las enfermedades del aparato digestivo (gastritis y úlcera ), tensión, ansiedad, problemas de espalda y la hipertensión. En este trabajo se propone una secuencia de actividad laboral (gimnasia) en el intervalo de tiempo pequeño, respetando las instalaciones y el espacio físico disponible en el ambiente del trabajo, como una estrategia para mejorar la calidad de vida laboral, para aumentar la productividad, mejorar la disposición a trabajar y para aumentar el conocimiento del cuerpo y de la interacción social.
Resumo:
This work proposes the use of a simple voltage divider circuit composed by one potentiometer and one resistor to simulate the behavior of the electrical output signal of linear and nonlinear sensors. It is a low cost way to implement practical experiments in classroom and it also enables the analysis of interesting topics of electricity. This work induces naturally to a class guide where students can build and characterize a voltage divider to explore several concepts about sensors output signal. As the result of this teaching activity it is expected that students understand fundamentals of voltage divider, potentiometer operation, fundamental sensor characteristics, transfer function, and, besides, associate directly concepts of physics and mathematics with a practical approach.
Resumo:
This paper presents results of stress cracking tests performed in high density polyethylene (HDPE) geomembranes (GM). Stress cracking tests were performed in accordance to ASTM D5397: Notched Constant Tensile Load Test (NCTL) and Single Point-Notched Constant Tensile Load Test (SP-NCTL). Tests were conducted to the fresh sample at 50ºC (standard test) and at 70ºC (accelerated condition) in order to compare the SC values. Results from accelerated tests (NCTL) showed, for instance, a total economy of 390 hours (comparing load stages of 25% yield stress) to perform the tests.
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Pós-graduação em Letras - IBILCE
Resumo:
Nitroglycerin (GIN) has been clinically used to treat angina pectoris and acute heart episodes for over 100 years. The effects of GTN have long been recognized and active research has contributed to the unraveling of numerous metabolic routes capable of converting GIN to the potent vasoactive messenger nitric oxide. Recently, the mechanism by which minute doses of GIN elicit robust pharmacological responses was revisited and eNOS activation was implicated as an important route mediating vasodilation induced by low GTN doses (1-50 nM). Here, we demonstrate that at such concentrations the pharmacologic effects of nitroglycerin are largely dependent on the phosphatidylinositol 3-kinase, Akt/PKB, and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) signal transduction axis. Furthermore, we demonstrate that nitroglycerin-dependent accumulation of 3,4,5-InsP(3), probably because of inhibition of PTEN, is important for eNOS activation, conferring a mechanistic basis for GIN pharmacological action at pharmacologically relevant doses. (C) 2011 Elsevier Inc. All rights reserved.
Resumo:
Glioblastoma multiforme (GBM) is the most aggressive of the astrocytic malignancies and the most common intracranial tumor in adults. Although the epidermal growth factor receptor (EGFR) is overexpressed and/or mutated in at least 50% of GBM cases and is required for tumor maintenance in animal models, EGFR inhibitors have thus far failed to deliver significant responses in GBM patients. One inherent resistance mechanism in GBM is the coactivation of multiple receptor tyrosine kinases, which generates redundancy in activation of phosphoinositide-3'-kinase (PI3K) signaling. Here we demonstrate that the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) tumor suppressor is frequently phosphorylated at a conserved tyrosine residue, Y240, in GBM clinical samples. Phosphorylation of Y240 is associated with shortened overall survival and resistance to EGFR inhibitor therapy in GBM patients and plays an active role in mediating resistance to EGFR inhibition in vitro. Y240 phosphorylation can be mediated by both fibroblast growth factor receptors and SRC family kinases (SFKs) but does not affect the ability of PTEN to antagonize PI3K signaling. These findings show that, in addition to genetic loss and mutation of PTEN, its modulation by tyrosine phosphorylation has important implications for the development and treatment of GBM.
Resumo:
Macrophage ingestion of the yeast Candida albicans requires its recognition by multiple receptors and the activation of diverse signaling programs. Synthesis of the lipid mediator prostaglandin E-2 (PGE(2)) and generation of cyclic adenosine monophosphate (cAMP) also accompany this process. Here, we characterized the mechanisms underlying PGE(2)-mediated inhibition of phagocytosis and filamentous actin (F-actin) polymerization in response to ingestion of C. albicans by alveolar macrophages. PGE(2) suppressed phagocytosis and F-actin formation through the PGE(2) receptors EP2 and EP4, cAMP, and activation of types I and II protein kinase A. Dephosphorylation and activation of the actin depolymerizing factor cofilin-1 were necessary for these inhibitory effects of PGE(2). PGE(2)-dependent activation of cofilin-1 was mediated by the protein phosphatase activity of PTEN (phosphatase and tensin homolog deleted on chromosome 10), with which it directly associated. Because enhanced production of PGE(2) accompanies many immunosuppressed states, the PTEN-dependent pathway described here may contribute to impaired antifungal defenses.
Resumo:
[ES]Thomas Merton (1915-1968) escritor y monje contemplativo de la Abadía de Getsemaní, del estado norteamericano de Kentucky, abandona temporalmente su comunidad monástica para emprender un gran viaje; un experimento que fundamentalmente tiene que ver con la fascinación de los secretos que Oriente custodiaba y que culminará siendo la asombrosa síntesis de su vida. Esa tensión hacia lo otro que se llama sed pero también se llama curiositas, le conducirá por una secuencia de caminos por Asia, hasta llegar a perderse en el laberinto de los colosos de Gal Vihara, una sucesión de estatuas gigantes de Buda, que aunque no pudieron redimirle de su trágico destino, consuma el inicio de una total transformación, de una total disolución en su percepción del mundo. Recorrer, aunque sólo sea de forma indicativa, las páginas de su admirable Diario es la intención de este estudio.
Resumo:
Máster Universitario en Eficiencia Energética (SIANI)
Resumo:
Class I phosphatidylinositol 3-kinases (PI3Ks) are heterodimeric lipid kinases consisting of a regulatory subunit and one of four catalytic subunits (p110α, p110β, p110γ or p110δ). p110γ/p110δ PI3Ks are highly enriched in leukocytes. In general, PI3Ks regulate a variety of cellular processes including cell proliferation, survival and metabolism, by generating the second messenger phosphatidylinositol-3,4,5-trisphosphate (PtdIns(3,4,5)P3). Their activity is tightly regulated by the phosphatase and tensin homolog (PTEN) lipid phosphatase. PI3Ks are widely implicated in human cancers, and in particular are upregulated in T-cell acute lymphoblastic leukemia (T-ALL), mainly due to loss of PTEN function. These observations lend compelling weight to the application of PI3K inhibitors in the therapy of T-ALL. At present different compounds which target single or multiple PI3K isoforms have entered clinical trials. In the present research, it has been analyzed the therapeutic potential of the pan-PI3K inhibitor BKM120, an orally bioavailable 2,6-dimorpholino pyrimidine derivative, which has entered clinical trials for solid tumors, on both T-ALL cell lines and patient samples. BKM120 treatment resulted in cell cycle arrest and apoptosis, being cytotoxic to a panel of T-ALL cell lines and patient T-lymphoblasts. Remarkably, BKM120 synergized with chemotherapeutic agents currently used for treating T-ALL patients. BKM120 efficacy was confirmed in in vivo studies to a subcutaneous xenotransplant model of human T-ALL. Because it is still unclear which agents among isoform-specific or pan inhibitors can achieve the greater efficacy, further analyses have been conducted to investigate the effects of PI3K inhibition, in order to elucidate the mechanisms responsible for the proliferative impairment of T-ALL. Overall, these results indicated that BKM120 may be an efficient treatment for T-ALLs that have aberrant up-regulation of the PI3K signaling pathway and strongly support clinical application of pan-class I PI3K rather than single-isoform inhibitors in T-ALL treatment.
Resumo:
The metabolic disorders that predispose patients to NASH (non-alcoholic steatohepatitis) include insulin resistance and obesity. Repeated hypoxic events, such as occur in obstructive sleep apnoea syndrome, have been designated as a risk factor in the progression of liver disease in such patients, but the mechanism is unclear, in particular the role of hypoxia. Therefore we studied the influence of hypoxia on the development and progression of steatohepatitis in an experimental mouse model. Mice with a hepatocellular-specific deficiency in the Pten (phosphatase and tensin homologue deleted on chromosome 10) gene, a tumour suppressor, were exposed to a 10% O2 (hypoxic) or 21% O2 (control) atmosphere for 7 days. Haematocrit, AST (aspartate aminotransferase), glucose, triacylglycerols (triglycerides) and insulin tolerance were measured in blood. Histological lesions were quantified. Expression of genes involved in lipogenesis and mitochondrial beta-oxidation, as well as FOXO1 (forkhead box O1), hepcidin and CYP2E1 (cytochrome P450 2E1), were analysed by quantitative PCR. In the animals exposed to hypoxia, the haematocrit increased (60+/-3% compared with 50+/-2% in controls; P<0.01) and the ratio of liver weight/body weight increased (5.4+/-0.2% compared with 4.7+/-0.3% in the controls; P<0.01). Furthermore, in animals exposed to hypoxia, steatosis was more pronounced (P<0.01), and the NAS [NAFLD (non-alcoholic fatty liver disease) activity score] (8.3+/-2.4 compared with 2.3+/-10.7 in controls; P<0.01), serum AST, triacylglycerols and glucose were higher. Insulin sensitivity decreased in mice exposed to hypoxia relative to controls. The expression of the lipogenic genes SREBP-1c (sterol-regulatory-element-binding protein-1c), PPAR-gamma (peroxisome-proliferator-activated receptor-gamma), ACC1 (acetyl-CoA carboxylase 1) and ACC2 (acetyl-CoA carboxylase 2) increased significantly in mice exposed to hypoxia, whereas mitochondria beta-oxidation genes [PPAR-alpha (peroxisome-proliferator-activated receptor-alpha) and CPT-1 (carnitine palmitoyltransferase-1)] decreased significantly. In conclusion, the findings of the present study demonstrate that hypoxia alone aggravates and accelerates the progression of NASH by up-regulating the expression of lipogenic genes, by down-regulating genes involved in lipid metabolism and by decreasing insulin sensitivity.
Resumo:
PURPOSE: Tumor stage and nuclear grade are the most important prognostic parameters of clear cell renal cell carcinoma (ccRCC). The progression risk of ccRCC remains difficult to predict particularly for tumors with organ-confined stage and intermediate differentiation grade. Elucidating molecular pathways deregulated in ccRCC may point to novel prognostic parameters that facilitate planning of therapeutic approaches. EXPERIMENTAL DESIGN: Using tissue microarrays, expression patterns of 15 different proteins were evaluated in over 800 ccRCC patients to analyze pathways reported to be physiologically controlled by the tumor suppressors von Hippel-Lindau protein and phosphatase and tensin homologue (PTEN). Tumor staging and grading were improved by performing variable selection using Cox regression and a recursive bootstrap elimination scheme. RESULTS: Patients with pT2 and pT3 tumors that were p27 and CAIX positive had a better outcome than those with all remaining marker combinations. A prolonged survival among patients with intermediate grade (grade 2) correlated with both nuclear p27 and cytoplasmic PTEN expression, as well as with inactive, nonphosphorylated ribosomal protein S6. By applying graphical log-linear modeling for over 700 ccRCC for which the molecular parameters were available, only a weak conditional dependence existed between the expression of p27, PTEN, CAIX, and p-S6, suggesting that the dysregulation of several independent pathways are crucial for tumor progression. CONCLUSIONS: The use of recursive bootstrap elimination, as well as graphical log-linear modeling for comprehensive tissue microarray (TMA) data analysis allows the unraveling of complex molecular contexts and may improve predictive evaluations for patients with advanced renal cancer.
Resumo:
The aim of our study was to investigate the phenomenon of intussusceptive angiogenesis with a focus on its molecular regulation by vascular endothelial growth factor receptor (VEGFR)/platelet-derived growth factor receptor β (PDGFRβ) pathways and biological significance for glomerular recovery after acute injury. Glomerular healing by intussusception was examined in a particular setting of Thy1.1 nephritis, where the lysis of mesangial cells results in an initial collapse and successive rebuilding of glomerular capillary structure. Restoration of capillary structure after induction of Thy1.1 nephritis occurred by intussusceptive angiogenesis resulting in i) rapid expansion of the capillary plexus with reinstatement of the glomerular filtration surface and ii) restoration of the archetypical glomerular vascular pattern. Glomerular capillaries of nephritic rats after combined VEGFR2 and PDGFRβ inhibition by PTK787/ZK222584 (PTK/ZK) were tortuous and irregular. However, the onset of intussusceptive angiogenesis was influenced only after long-term PTK/ZK treatment, providing an important insight into differential molecular regulation between sprouting and intussusceptive angiogenesis. PTK/ZK treatment abolished α-smooth muscle actin and tensin expression by injured mesangial cells, impaired glomerular filtration of microspheres, and led to the reduction of glomerular volume and the presence of multiple hemorrhages detectable in the tubular system. Collectively, treatment of nephritic patients with PTK/ZK compound is not recommended.