228 research outputs found

    Topographyc shadow influence on optical image acquired by satellite in the southern hemisphere

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    During image acquisition, is usually chosen scenes with a lesser cloud cover to avoid loss of spectral information. However, when training samples are collected for image classification, the user finds shadowed areas. Such situation is similar to the presence of clouds since spectral information of these classes is the same in all optical bands of the sensor. This fact becomes more pronounced in mountainous relief areas due to shadow projection on the terrain, which can vary among all seasons during the solar year. With the goal to obtain images with a lower presence of shadow, it was simulated, under the same relief conditions, shading variation in function of latitude (0° to 40° S). Solar radiation models were processed for the days and times passages of the Landsat TM and ETM+ satellite on the Southern Hemisphere. It was verified that over 30° S and 40° S latitudes, a loss of shading area varying between 27% to 91 % and that images should be preferentially taken between October and February. For latitudes comprising 0° and 10° S, the loss was considered negligible, when we set a 10% threshold of loss in the total valid area in an image. According to the amount of radiation in a terrain, South and West areas received less direct solar radiation over the year for all analyzed latitudes in the modeling

    One-year timeline kinetics of cytokine-mediated cellular immunity in dogs vaccinated against visceral leishmaniasis

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    BACKGROUND: The main control strategy for visceral leishmaniasis in Brazil has been based on the elimination of seropositive dogs, although this is not widely accepted. In this context, the use of a long-lasting protective vaccine against canine visceral leishmaniasis (CVL) has been highly expected. The aim of this work was to determine the timeline kinetics of the cytokine microenvironment derived from circulating leukocytes as supportive immunological biomarkers triggered by Leishmune® vaccine. Cross-sectional kinetic analysis of cellular immunity cytokines was carried out at three times (1, 6 and 12 months) after primovaccination with Leishmune®. In vitro short-term whole blood cultures were stimulated with Leishmania infantum soluble antigen (SLAg). The secreted cytokine signatures and their major sources were determined. RESULTS: At six months after vaccination, Leishmune® induced an increase in IL-8, IFN-γ, IL-17a and TNF-α levels and a decrease in IL-10. Cytokine signature analysis revealed a shift in the microenvironment towards a pro-inflammatory profile mediated by IL-8 and IFN-γ. Both, CD4(+) (↑TNF-α(+) and ↑IFN-γ (+)) and CD8(+) (↑IL-17a and ↓IL-4) T-cells contributed to the acquired immune responses observed after stimulation with SLAg. CONCLUSIONS: The changes observed in the cytokine profile suggested that Leishmune® was able to induce an effective response at six months after primovaccination. After one year, it returned to baseline suggesting the need of additional boosting

    Isolated familial somatotropinoma: 11q13-loh and gene/protein expression analysis suggests a possible involvement of aip also in non-pituitary tumorigenesis

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    OBJECTIVE: Non-pituitary tumors have been reported in a subset of patients harboring germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene. However, no detailed investigations of non-pituitary tumors of AIP-mutated patients have been reported so far. PATIENTS: We examined a MEN1- and p53-negative mother-daughter pair with acromegaly due to somatotropinoma. Subsequently, the mother developed a large virilizing adrenocortical carcinoma and a grade II B-cell non-Hodgkin's lymphoma. DESIGN: Mutational analysis was performed by automated sequencing. Loss-of-heterozygosity (LOH) analysis was carried out by sequencing and microsatellite analysis. AIP expression was assessed through quantitative PCR (qPCR) and immunohistochemistry. RESULTS: The functional inactivating mutation c.241C>T (R81X), which blocks the AIP protein from interacting with phosphodiesterase 4A (PDE4A), was identified in the heterozygous state in the leukocyte DNA of both patients. Analyzing the tumoral DNA revealed that the AIP wild-type allele was lost in the daughter's somatotropinoma and the mother's adrenocortical carcinoma. Both tumors displayed low AIP protein expression levels. Low AIP gene expression was confirmed by qPCR in the adrenocortical carcinoma. No evidence of LOH was observed in the DNA sample from the mother's B-cell lymphoma, and this tumor displayed normal AIP immunostaining. CONCLUSIONS: Our study presents the first molecular analysis of non-pituitary tumors in AIP-mutated patients. The finding of AIP inactivation in the adrenocortical tumor suggests that further investigation of the potential role of this recently identified tumor suppressor gene in non-pituitary tumors, mainly in those tumors in which the cAMP and the 11q13 locus are implicated, is likely to be worthwhile

    The genomes of two key bumblebee species with primitive eusocial organization

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    Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

    Cyclodextrin Complexes of Reduced Bromonoscapine in Guar Gum Microspheres Enhance Colonic Drug Delivery

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    Here, we report improved solubility and enhanced colonic delivery of reduced bromonoscapine (Red-Br-Nos), a cyclic ether brominated analogue of noscapine, upon encapsulation of its cyclodextrin (CD) complexes in bioresponsive guar gum microspheres (GGM). Phase−solubility analysis suggested that Red-Br-Nos complexed with β-CD and methyl-β-CD in a 1:1 stoichiometry, with a stability constant (Kc) of 2.29 × 103 M−1 and 4.27 × 103 M−1. Fourier transforms infrared spectroscopy indicated entrance of an O−CH2 or OCH3−C6H4−OCH3 moiety of Red-Br-Nos in the β-CD or methyl-β- CD cavity. Furthermore, the cage complex of Red-Br-Nos with β-CD and methyl-β-CD was validated by several spectral techniques. Rotating frame Overhauser enhancement spectroscopy revealed that the Ha proton of the OCH3−C6H4−OCH3 moiety was closer to the H5 proton of β-CD and the H3 proton of the methyl-β-CD cavity. The solubility of Red-Br-Nos in phosphate buffer saline (PBS, pH ∼ 7.4) was improved by ∼10.7-fold and ∼21.2-fold when mixed with β-CD and methyl-β-CD, respectively. This increase in solubility led to a favorable decline in the IC50 by ∼2-fold and ∼3-fold for Red-Br-Nos−β-CD-GGM and Red-Br-Nos−methyl-β-CD-GGM formulations respectively, compared to free Red-Br-Nos−β-CD and Red-Br-Nos−methyl-β-CD in human colon HT-29 cells. GGM-bearing drug complex formulations were found to be highly cytotoxic to the HT-29 cell line and further effective with simultaneous continuous release of Red-Br-Nos from microspheres. This is the first study to showing the preparation of drug-complex loaded GGMS for colon delivery of Red-Br-Nos that warrants preclinical assessment for the effective management of colon cancer

    Genome of Herbaspirillum seropedicae Strain SmR1, a Specialized Diazotrophic Endophyte of Tropical Grasses

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    The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme—GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species

    Cooperation between Apoptotic and Viable Metacyclics Enhances the Pathogenesis of Leishmaniasis

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    Mimicking mammalian apoptotic cells by exposing phosphatidylserine (PS) is a strategy used by virus and parasitic protozoa to escape host protective inflammatory responses. With Leishmania amazonensis (La), apoptotic mimicry is a prerogative of the intramacrophagic amastigote form of the parasite and is modulated by the host. Now we show that differently from what happens with amastigotes, promastigotes exposing PS are non-viable, non-infective cells, undergoing apoptotic death. As part of the normal metacyclogenic process occurring in axenic cultures and in the gut of sand fly vectors, a sub-population of metacyclic promastigotes exposes PS. Apoptotic death of the purified PS-positive (PSPOS) sub-population was confirmed by TUNEL staining and DNA laddering. Transmission electron microscopy revealed morphological alterations in PSPOS metacyclics such as DNA condensation, cytoplasm degradation and mitochondrion and kinetoplast destruction, both in in vitro cultures and in sand fly guts. TUNELPOS promastigotes were detected only in the anterior midgut to foregut boundary of infected sand flies. Interestingly, caspase inhibitors modulated parasite death and PS exposure, when added to parasite cultures in a specific time window. Efficient in vitro macrophage infections and in vivo lesions only occur when PSPOS and PS-negative (PSNEG) parasites were simultaneously added to the cell culture or inoculated in the mammalian host. The viable PSNEG promastigote was the infective form, as shown by following the fate of fluorescently labeled parasites, while the PSPOS apoptotic sub-population inhibited host macrophage inflammatory response. PS exposure and macrophage inhibition by a subpopulation of promastigotes is a different mechanism than the one previously described with amastigotes, where the entire population exposes PS. Both mechanisms co-exist and play a role in the transmission and development of the disease in case of infection by La. Since both processes confer selective advantages to the infective microorganism they justify the occurrence of apoptotic features in a unicellular pathogen
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