966 resultados para Vacuolar H -ATPase (V-ATPase)
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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.
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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.
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Calcium uptake by tonoplast enriched membrane vesicles from maize (Zea mays L. cv. LG 11) primary roots was studied. A pH gradient, measured by the fluorescence quenching of quinacrine, was generated across sealed vesicles driven by the pyrophosphate-dependent proton pump. The fluorescence quenching was strongly inhibited by Ca2+; moreover, when increasing Ca2+ concentrations were added to vesicles at steady-state, a concomitant decrease in the proton gradient was observed. Ca2+ uptake using Ca-45(2+) was linear from 10 min when oxalate (10 mM) was present, while Ca2+ uptake was completely inhibited with proton ionophores (FCCP and monensin), indicating a Ca2+/H+ antiport. Membranes were further fractionated using a linear sucrose density gradient (10-45%) and were identified with marker enzymes. Ca2+ uptake co-migrated with the tonoplast pyrophosphate-dependent proton pumping, pyrophosphatase and ATPase activities: the Ca2+/H+ antiport is consequently located at the tonoplast.
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The subcellular localization of a calmodulin-stimulated calcium (Ca2+)-ATPase activity from maize roots (Zea mays L., cv LG 11) was studied. For this purpose, an efficient procedure was developed to prepare sealed plasma membrane vesicles allowing the measurement of proton and Ca2+ transport activities. Two-day-old root membranes were fractionated by sucrose and dextran density gradient centrifugation. Marker enzymes were used to study the distribution of the different membranes in the gradients and a filtration technique was developed to measure Ca-45(2+) transport in sealed vesicles. Most of the ATP-dependent Ca2+ transport activity was associated with the ER. However, a small part of this activity was associated with the tonoplast (corresponding to the activity of the H+/Ca2+ antiport) and the plasma membrane. When the Ca2+ transport was measured in the presence of exogenous calmodulin (1 muM), a 3-5-fold increase of uptake was measured. The calmodulin-stimulated activity was associated with the tonoplast vesicles only. This activity was insensitive to monensin, a proton ionophore, ruling out a direct effect of calmodulin on the H+/Ca2+ antiport. In conclusion, four different Ca2+ transporters are present in young maize root cells. A Ca2+/H+ antiport system is present on the tonoplast, whereas, the plasma membrane and the ER possess each a calmodulinin-sensitive Ca2+-ATPase. Finally, a calmodulin-stimulated Ca2+-ATPase is associated with the tonoplast.
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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.
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The Immunity Related GTPases (IRG proteins) constitute a large family of interferon-inducible proteins that mediate early resistance to Toxoplasma gondii infection in mice. At least six members of this family are required for resistance of mice to virulent T. gondii strains. Recent results have shown that the complexity of the resistance arises from complex regulatory interactions between different family members. The mode of action against T. gondii depends on the ability of IRG proteins to accumulate on the parasitophorous vacuole of invading tachyzoites and to induce local damage to the vacuole resulting in disruption of the vacuolar membrane. Virulent strains of T. gondiiovercome the IRG resistance system, probably by interfering with the loading of IRG proteins onto the parasitophorous vacuole membrane. It may be assumed that T. gondii strains highly virulent for mice will be disadvantaged in the wild due to the rapid extinction of the infected host, while it is self-evident that susceptibility to virulent strains is disadvantageous to the mouse host. We consider the possibility that this double disadvantage is compensated in wild populations by segregating alleles with different resistance and susceptibility properties in the IRG system.
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One key step in gene expression is the biogenesis of mRNA ribonucleoparticle complexes (mRNPs). Formation of the mRNP requires the participation of a number of conserved factors such as the THO complex. THO interacts physically and functionally with the Sub2/UAP56 RNA-dependent ATPase, and the Yra1/REF1/ALY RNA-binding protein linking transcription, mRNA export and genome integrity. Given the link between genome instability and cancer, we have performed a comparative analysis of the expression patterns of THOC1, a THO complex subunit, and ALY in tumor samples.
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Background and aim: Wilson disease (WD) is an inherited disorder ofhepatic copper excretion leading to toxic accumulation of copper in theliver as well as the brain, cornea, and other organs. The defect is due tomutations of the copper-transporting ATPase ATP7B. Here, we describethe adult cases of hepatic WD diagnosed at the CHUV between 2005and 2010.Methods: Clinical manifestions, results of diagnostic tests, and follow-upof adult patients with hepatic WD were recorded systematically.Results: Seven new adult cases of hepatic WD were diagnosed in ourcenter between 2005 and 2010. Three were women and 4 men, with amedian a ge at d iagnosis o f 24 (range, 1 8-56) years. Three patientspresented with acute liver failure (ALF), three with persistently elevatedliver function tests, and one with a dvanced cirrhosis. None hadneurological manifestations. Only one patient, presenting with ALF, had aKayser-Fleischer corneal ring. Median ceruloplasmin levels at diagnosiswere 0.13 (range, <0.03-0.30) g/l, median 24 h urinary copper excretion6.3 (range, 0.4-62.0) μmol/24 h, and median hepatic copperconcentration 591 (range, 284-1049) μg/g. At least one mutation in theATP7B g ene was i dentified in a ll patients. Allelic frequency of t hecommon H1069Q mutation was 14%. Two patients presenting with ALFand the one with advanced cirrhosis underwent successful l ivertransplantation. One patient with ALF recovered under chelator therapy.D-penicillamine was used as first-line chelator treatment, with a switch totrientine due to adverse effects in 2 out of 4 patients u nder l ong-termtreatment.Conclusions: The clinical presentation of WD and the performance ofdiagnostic tests are variable. A high index of suspicion i n clinicallycompatible situations i s key, with a combination of tests allowing thediagnosis of WD.
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Microautophagy involves direct invagination and fission of the vacuolar/lysosomal membrane under nutrient limitation. This occurs by an autophagic tube, a specialized vacuolar membrane invagination that pinches off vesicles into the vacuolar lumen. In this study we have identified the VTC (vacuolar transporter chaperone) complex as required for microautophagy. The VTC complex is present on the ER and vacuoles and at the cell periphery. On induction of autophagy by nutrient limitation the VTC complex is recruited to and concentrated on vacuoles. The VTC complex is inhomogeneously distributed within the vacuolar membranes, showing an enrichment on autophagic tubes. Deletion of the VTC complex blocks microautophagic uptake into vacuoles. The mutants still form autophagic tubes but the production of microautophagic vesicles from their tips is impaired. In line with this, affinity-purified antibodies to the Vtc proteins inhibit microautophagic uptake in a reconstituted system in vitro. Our data suggest that the VTC complex is an important constituent of autophagic tubes and that it is required for scission of microautophagic vesicles from these tubes.
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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)
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En port.: Unidad Estadística
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Resistance of Helicobacter pylori to clarithromycin is characterised by simple point mutations in the 23S ribosomal RNA (rRNA) gene and is responsible for the majority of cases of failure to eradicate this bacterium. In this paper, we characterised the variability of the 23S rRNA gene in biopsies of patients with gastric pathologies in the eastern Amazon (Northern Region of Brazil) using PCR and sequencing. A total of 49 sequences of H. pylori strains were analysed and of those, 75.6% presented nucleotide substitutions: A2142G (3.3%), T2182C (12.9%), G2224A (6.45%), T2215C (61.3%), A2192G (3.3%), G2204C (6.4%) and T2221C (6.4%). Of the mutations identified, four are known mutations related to cases of resistance and 16.1% are not yet described, revealing a high prevalence of mutations in the H. pylori 23S rRNA gene among the strains circulating in the in the eastern Amazon. The high prevalence in individuals with gastric pathologies in the Northern Region of Brazil demonstrates the need for characterising the profile of these strains to provide correct therapy for patients, considering that mutations in this gene are normally associated with resistance to the primary medication used in controlling H. pylori infection.
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Colbertinus