8 resultados para Cenci, Beatrice, 1577-1599.

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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Genetic instability is frequent in human cancer. Unscheduled tetraploidization can trigger cell transformation and tumorigenesis. We made a cytogenetic analysis by Giemsa-trypsin banding of a stage I, biphasic Wilms tumor diagnosed in a 10-month-old male. An evident karyotypic heterogeneity was found. Four different subclones of tumor cells were observed, with DNA content varying from diploid to near-tetraploid complements. The genetic events involved in the acquisition of aneuploidy in Wilms tumor remain unclear. We hypothesize that initial tetraploidization caused aberrant cell division, leading to abnormal chromosomal segregation, cell transformation and tumorigenesis.

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The effect of binding Tb(3+) to sodium taurocholate aggregates containing polyaromatic hydrocarbon guests was examined using pyrene and 1-ethylnaphthalene as guests that bind to the primary aggregate, and 1-naphthyl-1-ethanol as a secondary aggregate guest. Time-resolved fluorescence quenching studies were used to study the binding site properties, while laser flash photolysis quenching studies provided information on the dynamics of the guest-aggregate system. Both the primary and secondary aggregate binding sites became more compact in the presence of bound Tb(3+), while only the primary aggregate became more accessible to anionic molecules. The binding dynamics for the guest-primary aggregate system became faster when Tb(3+) was bound to the aggregate. In contrast, for the guest-secondary aggregate the presence of Tb(3+) resulted in a small decrease in the dissociation rate constant. The influence of bound Tb(3+) on the primary and secondary bile salt aggregates is significantly different, which affects how these aggregates can be used as supramolecular host systems to modify guest reactivity.

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The objective of this work was to characterize the delignification effluent originating from the delignification industry and evaluate the combination of the fungus and photocatalytic process (TiO(2)/UV system) for the treatment of this effluent. The delignification effluent has proven harmful to the environment because it presents high color (3516 CU), total phenol (876 mg/L and TOC (1599 mg/L) and is also highly toxic even in a low concentration. The results of photocatalysis were 11%, 25% and 13% higher for reductions in color, total phenol and TOC, respectively. The combined treatments presented benefits when compared to the non-combined treatments. Fungus and photocatalysis in combination proved to be the best treatment, reducing the color, total phenol, toxicity (inhibition of Escherichia coli growth) and TOC by 94.2%, 92.6%, 4.9% and 62%, respectively. (C) 2008 Elsevier B.V. All rights reserved.

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Before one models the effect of plastic deformation on magnetoacoustic emission (MAE), one must first treat non-180 degrees domain wall motion. In this paper, we take the Alessandro-Beatrice-Bertotti-Montorsi (ABBM) model and modify it to treat non-180 degrees wall motion. We then insert a modified stress-dependent Jiles-Atherton model, which treats plastic deformation, into the modified ABBM model to treat MAE and magnetic Barkhausen noise (HBN). In fitting the dependence of these quantities on plastic deformation, we apply a model for when deformation gets into the stage where dislocation tangles are formed, noting two chief effects, one due to increased density of emission centers owing to increased dislocation density, and the other due to a more gentle increase in the residual stress in the vicinity of the dislocation tangles as deformation is increased.

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Magnetic energy losses and permeability have been investigated in laboratory prepared and commercial Mn-Zn sintered ferrites from quasi-static conditions up to 10 MHz. The mechanisms leading to energy dissipation, either due to domain wall displacements or magnetization rotations, have been quantitatively assessed and their respective roles have been clarified. Domain wall processes dissipate energy by pure relaxation effects, while rotations display resonant absorption of energy over a broad range of frequencies. Their specific contributions to the permeability and its frequency dispersion are thus identified and separately evaluated. It is shown that eddy currents are always too weak to appreciably contribute to the losses over the whole investigated frequency range and that rotations are the dominant magnetization and loss producing mechanisms on approaching the MHz range, as predicted by the Landau-Lifshitz-Gilbert equation with distributed anisotropy fields. (C) 2008 Elsevier B.V. All rights reserved.

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Context: Isolated heterozygous SHOX defects are the most frequent monogenic cause of short stature, and combined therapy with recombinant human GH (rhGH) and GnRH analog (GnRHa) in pubertal patients has been suggested, but there are no data on final height. Objective: The aim of the study was to analyze adult height after rhGH and GnRHa therapy in patients with SHOX haploinsufficiency. Patients: Ten peripubertal patients with isolated SHOX defects participated in the study. Intervention: Five patients were followed without treatment, and five were treated with rhGH (50 mu g/kg/d) and depot leuprolide acetate (3.75 mg/month). Main Outcome Measures: Adult height SD score (SDS) was measured. Results: All patients followed without treatment had marked downward growth shift during puberty (height SDS, -1.2 +/- 0.7 at 11.4 +/- 1.4 yr; adult height SDS, -2.5 +/- 0.5). Conversely, four of five patients treated with rhGH for 2 to 4.9 yr associated to GnRHa for 1.4 to 5.8 yr improved their height SDS from -2.3 +/- 1.3 at 11.8 +/- 2.1 yr to a final height SDS of -1.7 +/- 1.6. The difference between the mean height SDS at the first evaluation and final height SDS was statistically significant in nontreated vs. treated patients (mean height SDS change, -1.2 +/- 0.4 vs. 0.6 +/- 0.4, respectively; P < 0.001). Conclusion: A gain in adult height of patients with isolated SHOX defects treated with combined rhGH and GnRHa therapy was demonstrated for the first time, supporting this treatment for children with SHOX defects who have just started puberty to avoid the loss of growth potential observed in these patients during puberty. (J Clin Endocrinol Metab 95: 328-332, 2010)

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Objective: Null genotypes of glutathione S-transferase (GSTs) exhibit absence of enzymatic activity and are hypothesized to modulate an increased risk of developing cardiovascular disease. The aim of this study was to identify the potential association between GSTM1 and GSTT1 deleted polymorphisms with cardiovascular risk factors and coronary atherosclerosis in two independent urban populations. Methods and results: Genotype distribution of GSTM1 and GSTT1 deleted polymorphism were examined in a sample of 1577 individuals from the general population and a replication sample of 871 individuals submitted to coronary angiography. Triglycerides, HDL-cholesterol and the triglycerides/HDL ratio were significantly associated with a double-deleted genotype in individuals from the general population. These findings were replicated in a second, independent, population of individuals submitted to coronary angiography. In addition, coronary artery disease severity was also associated with GSTs genotypes and the risk conferred from GSTs genotype was mainly due to triglycerides/HDL ratio information. Conclusions: The data suggest that the presence of a double deletion genotypes of the GSTM1 and GSTT1 genes is associated with hypertriglyceridemia and low HDL-cholesterol levels in humans. These novel findings may provide a new unexplored link between lipid metabolism and GST homeostasis. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

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We have identified a globally important clonal complex of Mycobacterium bovis by deletion analysis of over one thousand strains from over 30 countries. We initially show that over 99% of the strains of M. bovis, the cause of bovine tuberculosis, isolated from cattle in the Republic of Ireland and the UK are closely related and are members of a single clonal complex marked by the deletion of chromosomal region RDEu1 and we named this clonal complex European 1 (Eu1). Eu1 strains were present at less than 14% of French, Portuguese and Spanish isolates of M. bovis but are rare in other mainland European countries and Iran. However, strains of the Eu1 clonal complex were found at high frequency in former trading partners of the UK (USA, South Africa, New Zealand, Australia and Canada). The Americas, with the exception of Brazil, are dominated by the Eu1 clonal complex which was at high frequency in Argentina, Chile, Ecuador and Mexico as well as North America. Eu1 was rare or absent in the African countries surveyed except South Africa. A small sample of strains from Taiwan were non-Eu1 but, surprisingly, isolates from Korea and Kazakhstan were members of the Eu1 clonal complex. The simplest explanation for much of the current distribution of the Eu1 clonal complex is that it was spread in infected cattle, such as Herefords, from the UK to former trading partners, although there is evidence of secondary dispersion since. This is the first identification of a globally dispersed clonal complex M. bovis and indicates that much of the current global distribution of this important veterinary pathogen has resulted from relatively recent International trade in cattle. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.