278 resultados para Physiographic compartmentalization


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Objective: We evaluated whether chronic exposure to immunosuppression in transplant recipients modulate the placental inflammatory cytokine levels associated to gestational tolerance mechanisms. Methods: Serum samples were collected from 12 renal transplanted pregnant under immunosuppressive regimen treatment and 10 healthy women in second/third trimester of gestation. Term placental tissues (decidua and chorionic villi) were also obtained after elective caesarean. Serum IL-1β, IL-6, IL-8, IL-12p70 and TNF-α were measured, as also in placental homogenates, by Cytometric Bead Array (CBA) combined with flow cytometry and, TGF-β and IL-18 were measured by ELISA. Results: Serum levels of IL-6 (p=0.0001) and TNF-α (0.0112) were higher in the 2nd and 3rd trimesters and in decidua the spectrum of increased pro inflammatory cytokines was wider: IL-1β (p=0.0001), IL-6 (p=0.0001), IL-8 (p=0.0001), IL-12p70 (p=0.0001), TGF-β (p=0.0089) and TNF-α (p=0.0002). TGF-β1 was particularly increased in decidual compartment (p=0.001). In the chorionic villous, pro inflammatory profile also were maintained. High IL-1β (p=0.0001), IL-6 (p=0.0001), IL-8 (p=0.0001) and TNF-α (p=0.0001) levels establish a similar pattern to that seem in decidua. Conclusion: Immunosuppressors may impair the immune response, but when associated with pregnancy the cytokine levels seems to shift a proinflammatory profile in placental compartments, which might also impact on the gestational outcomes in transplanted mothers. © 2013 Informa UK Ltd. All rights reserved: reproduction in whole or part not permitted.

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Pós-graduação em Geociências e Meio Ambiente - IGCE

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Pós-graduação em Geociências e Meio Ambiente - IGCE

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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In Leishmania, de novo polyamine synthesis is initiated by the cleavage of L-arginine to urea and L-ornithine by the action of arginase (ARG, E.C. 3.5.3.1). Previous studies in L. major and L. mexicana showed that ARG is essential for in vitro growth in the absence of polyamines and needed for full infectivity in animal infections. The ARG protein is normally found within the parasite glycosome, and here we examined whether this localization is required for survival and infectivity. First, the localization of L. amazonensis ARG in the glycosome was confirmed in both the promastigote and amastigote stages. As in other species, arg(-) L. amazonensis required putrescine for growth and presented an attenuated infectivity. Restoration of a wild type ARG to the arg(-) mutant restored ARG expression, growth and infectivity. In contrast, restoration of a cytosol-targeted ARG lacking the glycosomal SKL targeting sequence (arg Delta SKL) restored growth but failed to restore infectivity. Further study showed that the ARG Delta SKL protein was found in the cytosol as expected, but at very low levels. Our results indicate that the proper compartmentalization of L. amazonensis arginase in the glycosome is important for enzyme activity and optimal infectivity. Our conjecture is that parasite arginase participates in a complex equilibrium that defines the fate of L-arginine and that its proper subcellular location may be essential for this physiological orchestration.

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In questo lavoro di tesi è presentato un metodo per lo studio della compartimentalizzazione dell’acqua in cellule biologiche, mediante lo studio dell’autodiffusione delle molecole d’acqua tramite uno strumento NMR single-sided. Le misure sono state eseguite nel laboratorio NMR all’interno del DIFA di Bologna. Sono stati misurati i coefficienti di autodiffusione di tre campioni in condizione bulk, ottenendo risultati consistenti con la letteratura. È stato poi analizzato un sistema cellulare modello, Saccharomyces cerevisiae, allo stato solido, ottimizzando le procedure per l’ottenimento di mappe di correlazione 2D, aventi come assi il coefficiente di autodiffusione D e il tempo di rilassamento trasversale T2. In questo sistema l’acqua è confinata e l’autodiffusione è ristretta dalle pareti cellulari, si parla quindi di coefficiente di autodiffusione apparente, Dapp. Mediante le mappe sono state individuate due famiglie di nuclei 1H. Il campione è stato poi analizzato in diluizione in acqua distillata, confermando la separazione del segnale in due distinte famiglie. L’utilizzo di un composto chelato, il CuEDTA, ha permesso di affermare che la famiglia con il Dapp maggiore corrisponde all’acqua esterna alle cellule. L’analisi dei dati ottenuti sulle due famiglie al variare del tempo lasciato alle molecole d’acqua per la diffusione hanno portato alla stima del raggio dei due compartimenti: r=2.3±0.2µm per l’acqua extracellulare, r=0.9±0.1µm per quella intracellulare, che è probabilmente acqua scambiata tra gli organelli e il citoplasma. L’incertezza associata a tali stime tiene conto soltanto dell’errore nel calcolo dei parametri liberi del fit dei dati, è pertanto una sottostima, dovuta alle approssimazioni connesse all’utilizzo di equazioni valide per un sistema poroso costituito da pori sferici connessi non permeabili. Gli ordini di grandezza dei raggi calcolati sono invece consistenti con quelli osservabili dalle immagini ottenute con il microscopio ottico.

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The compartmentalization of small ruminant lentivirus (SRLV) subtype A (Maedi-Visna virus) and B (caprine arthritis-encephalitis virus) variants was analyzed in colostrum and peripheral blood mononuclear cells of four naturally infected goats. Sequence analysis of DNA and RNA encompassing the V4-V5 env regions showed a differential distribution of SRLV variants between the two compartments. Tissue-specific compartmentalization was demonstrated by phylogenetic analysis in three of the four cases. In these animals colostrum proviral sequences were clustered relative to the blood viral sequences. In one goat, the blood and colostrum-derived provirus sequences were intermingled, suggesting trafficking of virus between the two tissues or mirroring a recent infection. Surprisingly, the pattern of free virus variants in the colostrum of all animals corresponded only partially to that of the proviral form, suggesting that free viruses might not derive from infected colostral cells. The compartmentalization of SRLV between peripheral blood and colostrum indicates that lactogenic transmission may involve specific viruses not present in the proviral populations circulating in the blood.

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Millions of years of physiographic changes have conditioned us to the fact that our present drainage is a temporary feature. Rivers once flowing opposite to their present direction is not an unusual condition for physiographers to suggest.

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Three cycles of erosion have modified the Boulder batholith. The earliest cycle produced a peneplaination that has been largely obliterated by a partially completed intermediate cycle, and the recent cycle now in progress.

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Lmx1b encodes a LIM-homeodomain transcription factor required for dorso-ventral (D-V) patterning in the mesenchyme of the vertebrate limb. In the absence of Lmx1b function, limbs exhibit a bi-ventral pattern indicating that Lmx1b is required for cells to adopt a dorsal cell fate. However, how Lmx1b specifies dorsal cell fates in the mesenchyme of the distal limb is unknown. Lmx1b is initially expressed throughout the dorsal and ventral limb bud mesenchyme, then becomes dorsally restricted around E10.5. At this stage, there is a sharp boundary between Lmx1b expressing and Lmx1b non-expressing cells. How the dorso-ventral Lmx1b expression boundary is formed and maintained is currently unknown. One mechanism that may contribute to establishing and/or maintaining the Lmx1b expression boundary is if the dorsal mesenchyme is a lineage-based compartment, where different groups of non-mingling cells are separated. Compartment formation has been proposed to rely on compartment-specific selector gene activity which functions to restrict cells to a compartment and specifies the identity of cells within that compartment. Based on the evidence that the dorsal limb identity relies on the expression of Lmx1b in the dorsal half of the limb mesenchyme, we hypothesized that Lmx1b might function as a dorsal limb bud mesenchyme selector gene to set up a dorsal compartment. To test this hypothesis, we developed an inducible CreERT2/ loxP based fate mapping approach that permanently marks Lmx1b wild-type and mutant cells and examined the distribution of their descendents in the developing limb. Our data is the first to show that dorso-ventral lineage compartments exist in the limb bud mesenchyme. Furthermore, Lmx1b is required for maintenance of the dorso-ventral compartment lineage boundary. The behavior of Lmx1b mutant cells that cross into the ventral mesenchyme, as well as previous chimera analysis in which mutant cells spread evenly in the ventral limb and form patches in the dorsal side, suggest that cell affinity differences prevent intermingling of dorsal and ventral cells. ^

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Live-imaging techniques (LIT) utilize target-specific fluorescent dyes to visualize biochemical processes using confocal and multiphoton scanning microscopy, which are increasingly employed as non-invasive approach to physiological in-vivo and ex-vivo studies. Here we report application of LIT to bivalve gills for ex-vivo analysis of gill physiology and mapping of reactive oxygen (ROS) and nitrogen (RNS) species formation in the living tissue. Our results indicate that H2O2, HOO. and ONOO- radicals (assessed through C-H2DFFDA staining) are mainly formed within the blood sinus of the filaments and are likely to be produced by hemocytes as defense against invading pathogens. The oxidative damage in these areas is controlled by enhanced CAT (catalase) activities recorded within the filaments. The outermost areas of the ciliated epithelial cells composing the filaments, concentrated the highest mitochondrial densities (MTK Deep Red 633 staining) and the most acidic pH values (as observed with ageladine-a). These mitochondria have low (depolarized) membrane potentials (D psi m) (JC-1 staining), suggesting that the high amounts of ATP required for ciliary beating may be in part produced by non-mitochondrial mechanisms, such as the enzymatic activity of an ATP-regenerating kinase. Nitric oxide (NO, DAF-2DA staining) produced in the region of the peripheral mitochondria may have an effect on mitochondrial electron transport and possibly cause the low membrane potential. High DAF-2DA staining was moreover observed in the muscle cells composing the wall of the blood vessels where NO may be involved in regulating blood vessel diameter. On the ventral bend of the gills, subepithelial mucus glands (SMG) contain large mucous vacuoles showing higher fluorescence intensities for O2.- (DHE staining) than the rest of the tissue. Given the antimicrobial properties of superoxide, release of O2.- into the mucus may help to avoid the development of microbial biofilms on the gill surface. However, cells of the ventral bends are paying a price for this antimicrobial protection, since they show significantly higher oxidative damage, according to the antioxidant enzyme activities and the carbonyl levels, than the rest of the gill tissue. This study provides the first evidence that one single epithelial cell may contain mitochondria with significantly different membrane potentials. Furthermore, we provide new insight into ROS and RNS formation in ex-vivo gill tissues which opens new perspectives for unraveling the different ecophysiological roles of ROS and RNS in multifunctional organs such as gills.

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Artículo a partir de extractos de la memoria del proyecto de rehabilitación de las nave 17 y 18 de Matadero Madrid