996 resultados para V-ATPase
Resumo:
Older people have the greatest barriers (mostly in terms of ability/opportunity) to participating in exercise, and thus have the highest incidence of decreased ease in carrying out tasks of daily living. In an ageing society, the negative effects of age on skeletal muscle performance would be reduced if compliance to exercise regimens could be encouraged through simple advice on timing, duration, frequency, intensity, as well as appropriate nutritional interventions. Research into the impact of optimal nutrition/diet supplementation in young and/or athletic populations is extensive. Such data are scarce when considering healthy, older populations. We therefore propose to investigate the impact of healthy eating habits with or without supplementation, on exercise responsiveness. This protocol seeks to maximise training benefits on the neural muscular and tendinous complexes.
Resumo:
Despite the presence of tumor-specific effector cells in the circulation of cancer patients, the immune response of the majority of these patients is not sufficient to prevent the growth and spread of their tumors. That tumor cells can be killed in vitro by tumor-reactive cytotoxic T cells is testimony to the fact that the tumors are not inherently resistant to T cell killing, but rather that there is a failure in immune recognition and effector cell activation. Many reasons for this failure of the body's defense system have been suggested, including the inability of tumor-reactive lymphocytes to migrate to tumor tissue. Here we designed a strategy to improve homing of primary lymphocytes into vascularized tumors. As a homing molecule we selected the integrin alpha v beta 3 since it is expressed by angiogenic vascular endothelium in tumors. To promote lymphocyte adhesion to alpha v beta 3 we "painted" primary lymphocytes with a recombinant, glycosylphosphatidylinositol-linked high-affinity ligand for alpha v beta 3. These painted lymphocytes specifically bound to alpha v beta 3 in vitro and homed to vascularized, solid tumors in vivo. This novel strategy may provide a significant advance in anti-tumor treatment such as adoptive immune therapy.
Resumo:
Amb aquest projecte s'ha portat a terme la planificació i el desenvolupament d'una aplicació web amb tecnologia J2EE. Es tracta d'un sistema que s'assimila a una eina de gestió de coneixement, ja que permet l'emmagatzematge de dades i coneixement en estructures arborescents. Posteriorment es pot accedir a aquest coneixement molt fàcilment, de manera que persones amb poca o nul·la formació en la matèria poden diagnosticar i, fins i tot, resoldre problemes relacionats amb la temàtica de la informació emmagatzemada.
Resumo:
BALB/c mice develop aberrant T helper 2 (Th2) responses and suffer progressive disease after infection with Leishmania major. These outcomes depend on the production of interleukin-4 (IL-4) early after infection. Here we demonstrate that the burst of IL-4 mRNA, peaking in draining lymph nodes of BALB/c mice 16 hr after infection, occurs within CD4+ T cells that express V beta 4 V alpha 8 T cell receptors. In contrast to control and V beta 6-deficient BALB/c mice, V beta 4-deficient BALB/c mice were resistant to infection, demonstrating the role of these cells in Th2 development. The early IL-4 response was absent in these mice, and T helper 1 responses occurred following infection. Recombinant LACK antigen from L. major induced comparable IL-4 production in V beta 4 V alpha 8 CD4+ cells. Thus, the IL-4 required for Th2 development and susceptibility to L. major is produced by a restricted population of V beta 4 V alpha 8 CD4+ T cells after cognate interaction with a single antigen from this complex organism.
Resumo:
Na,K-ATPase, the main active transport system for monovalent cations in animal cells, is responsible for maintaining Na(+) and K(+) gradients across the plasma membrane. During its transport cycle it binds three cytoplasmic Na(+) ions and releases them on the extracellular side of the membrane, and then binds two extracellular K(+) ions and releases them into the cytoplasm. The fourth, fifth, and sixth transmembrane helices of the alpha subunit of Na,K-ATPase are known to be involved in Na(+) and K(+) binding sites, but the gating mechanisms that control the access of these ions to their binding sites are not yet fully understood. We have focused on the second extracellular loop linking transmembrane segments 3 and 4 and attempted to determine its role in gating. We replaced 13 residues of this loop in the rat alpha1 subunit, from E314 to G326, by cysteine, and then studied the function of these mutants using electrophysiological techniques. We analyzed the results using a structural model obtained by homology with SERCA, and ab initio calculations for the second extracellular loop. Four mutants were markedly modified by the sulfhydryl reagent MTSET, and we investigated them in detail. The substituted cysteines were more readily accessible to MTSET in the E1 conformation for the Y315C, W317C, and I322C mutants. Mutations or derivatization of the substituted cysteines in the second extracellular loop resulted in major increases in the apparent affinity for extracellular K(+), and this was associated with a reduction in the maximum activity. The changes produced by the E314C mutation were reversed by MTSET treatment. In the W317C and I322C mutants, MTSET also induced a moderate shift of the E1/E2 equilibrium towards the E1(Na) conformation under Na/Na exchange conditions. These findings indicate that the second extracellular loop must be functionally linked to the gating mechanism that controls the access of K(+) to its binding site.
Resumo:
The pentavalent antimonies, mainly the meglumine antimoniate, are recommends as first-choice medicines for leishmaniasis therapy. In this work we described the development of formulations of meglumine antimoniate injectable medication, as well as the analytical methodology used in the selective determination of Sb(III) and Sb(Total) by hydride generation - inductively coupled plasma atomic emission spectrometry (HG-ICP-AES) and ICP-AES, respectively. On that purpose the analytical methodology was developed focusing on the HG-ICP-AES technique. The formulations using propylene glycol/water as vehicles in a 20:80 proportion were more appropriate for subsequent use in industrial scale. These formulations also showed a lower variation on Sb(III) percentage, no need of buffer solution to stabilize the formulation and no influence of the autoclaving in the quality of the product. The results of the development of the analytical methodology point out the proposed method as an efficient alternative for the determination of Sb(III) in the presence of large quantities of Sb(V) in injectable solutions of meglumine antimoniate, in a selective, linear, accurate and precise manner. In addition, the method showed a low limit of quantification, less interference of the matrix, and more resilience than batch techniques proposed in the Brazilian Pharmacopeia.
Resumo:
The reintroduction of dengue virus type 3 (DENV-3) in Brazil in 2000 and its subsequent spread throughout the country was associated with genotype III viruses, the only DENV-3 genotype isolated in Brazil prior to 2002. We report here the co-circulation of two different DENV-3 genotypes in patients living in the Northern region of Brazil during the 2002-2004 epidemics. Complete genomic sequences of viral RNA were determined from these epidemics, and viruses belonging to genotypes V (Southeast Asia/South Pacific) and III were identified. This recent co-circulation of different DENV-3 genotypes in South America may have implications for pathological and epidemiological dynamics.
Resumo:
Introduction: Pandemic Influenza A (H1N1)v pneumonia has led to a notable increase of admissions to intensive care units. A cytokine-mediated inflammatory response has been well documented in pneumonia and acute respiratory distress syndrome. However, few studies have focused on the role of these inflammatory mediators in infections caused by the Influenza A (H1N1)v. In this study, we assess the inflammatory response mediated by cytokines at the local and systemic levels in three cases of severe pneumonia caused by Influenza A (H1N1) virus. Methodology: Serum and bronchoalveolar lavage samples were obtained from three mechanically ventilated patients diagnosed with Influenza A (H1N1) virus pneumonia by bronchoscopic bronchoalveolar lavage. Levels of interleukin 6 (IL-6), interleukin 8 (IL-8), tumour necrosis factor alpha (TNFα) and interleukin 1 beta (IL-1ß) were meassured in these samples by enzyme-linked immunosorbent assay (ELISA). Results: High levels of C Reactive Protein, Procalcitonin below 1 ng/ml and absence of leukocytosis were common findings in all patients. TNF α and IL-1ß were not detected in the serum. IL-6 levels in serum were (94, pg/ml, 77 pg/ml and 84 pg/ml) respectively in the three patients, while IL-8 levels were (30,2 pg/ml, 128 pg/ml and 40,5 pg/ml). In the BAL samples, only one of the analysed cytokines, IL-1ß was present at detectable levels in two patients (21 pg/ml and 11 pg/ml respectively). Conclusions: Our results support previous findings which suggest that high levels of IL-6 and IL-8 in serum somehow participate in the inflammatory response in severe cases of pandemic influenza pneumonia.
Resumo:
En port.: Unidad Estadística. Publicado en la página web de la Consejería de Salud: www.juntadeandalucia.es/salud (Consejería de Salud / Profesionales / Estadísticas Sanitarias / Estadísticas de interrupción voluntaria del embarazo > Acceso a las Estadisticas de Interrupción Voluntaria del Embarazo)
Resumo:
En port.: Unidad Estadística