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81.
Pereira-Lorenzo S Costa RM Ramos-Cabrer AM Ciordia-Ara M Ribeiro CA Borges O Barreneche T 《Génome》2011,54(4):301-315
This is a large-scale molecular study based on simple sequence repeat (SSR) loci of the diversification process in chestnut cultivars from Portugal and Spain, from the northern Iberian Peninsula to the Canary Islands and the Azores. A total of 593 grafted chestnut trees (Castanea sativa Mill.) were analysed with 10 SSRs: 292 from Portugal and 301 from Spain. Some of the trees studied were more than 300 years old. Accessions were analysed using a model-based Bayesian procedure to assess the geographical structure and to assign individuals to reconstructed populations based on the SSR genotypes. We found 356 different genotypes with a mean value of clonality of 33% owing to grafting. Mutations accounted for 6%, with hybridization being the main diversification process that can explain the great diversity found. Ten main cultivar groups were detected: four in northern Spain, five in the centre of the Iberian Peninsula, and one in southern Spain related to the centre of the Iberian Peninsula. This work demonstrated that cultivar origin and the diversification process was a combination of clonal propagation of selected seedlings, hybridization, and mutations, which allowed high levels of diversity to be maintained with respect to selected clones for fruit production. Furthermore, seedlings and graft sticks facilitated the transport to new destinations in the colonization process, transporting sometimes more than 3000 km if we consider the Azores and the Canary Islands. 相似文献
82.
Kinzel O Alfieri A Altamura S Brunetti M Bufali S Colaceci F Ferrigno F Filocamo G Fonsi M Gallinari P Malancona S Hernando JI Monteagudo E Orsale MV Palumbi MC Pucci V Rowley M Sasso R Scarpelli R Steinkühler C Jones P 《Bioorganic & medicinal chemistry letters》2011,21(15):4429-4435
The Hedgehog (Hh-) signaling pathway is a key developmental pathway which gets reactivated in many human tumors, and smoothened (Smo) antagonists are emerging as novel agents for the treatment of malignancies dependent on the Hh-pathway, with the most advanced compounds demonstrating encouraging results in initial clinical trials. A novel series of potent bicyclic hydantoin Smo antagonists was reported in the preceding article, these have been resolved, and optimized to identify potent homochiral derivatives with clean off-target profiles and good pharmacokinetic properties in preclinical species. While showing in vivo efficacy in mouse allograft models, unsubstituted bicyclic tetrahydroimidazo[1,5-a]pyrazine-1,3(2H,5H)-diones were shown to epimerize in plasma. Alkylation of the C-8 position blocks this epimerization, resulting in the identification of MK-5710 (47) which was selected for further development. 相似文献
83.
da Costa Francez PA Rodrigues EM Frazão GF Dos Reis Borges ND Dos Santos SE 《Genetics and molecular biology》2011,34(1):35-39
The allelic frequencies of 12 short tandem repeat loci were obtained from a sample of 307 unrelated individuals living in Macapá, a city in the northern Amazon region, Brazil. These loci are the most commonly used in forensics and paternity testing. Based on the allele frequency obtained for the population of Macapá, we estimated an interethnic admixture for the three parental groups (European, Native American and African) of, respectively, 46%, 35% and 19%. Comparing these allele frequencies with those of other Brazilian populations and of the Iberian Peninsula population, no significant distances were observed. The interpopulation genetic distances (F(ST) coefficients) to the present database ranged from F(ST) = 0.0016 between Macapá and Belém to F(ST) = 0.0036 between Macapá and the Iberian Peninsula. 相似文献
84.
Calvete JJ Sanz L Pérez A Borges A Vargas AM Lomonte B Angulo Y Gutiérrez JM Chalkidis HM Mourão RH Furtado MF Moura-Da-Silva AM 《Journal of Proteomics》2011,74(4):510-527
We describe two geographically differentiated venom phenotypes across the wide distribution range of Bothrops atrox, from the Colombian Magdalena Medio Valley through Puerto Ayacucho and El Paují, in the Venezuelan States of Amazonas and Orinoquia, respectively, and S?o Bento in the Brazilian State of Maranh?o. Colombian and Venezuelan venoms show an ontogenetic toxin profile phenotype whereas Brazilian venoms exhibit paedomorphic phenotypes. Venoms from each of the 16 localities sampled contain both population-specific toxins and proteins shared by neighboring B. atrox populations. Mapping the molecular similarity between conspecific populations onto a physical map of B. atrox range provides clues for tracing dispersal routes that account for the current biogeographic distribution of the species. The proteomic pattern is consistent with a model of southeast and southwest dispersal and allopatric fragmentation northern of the Amazon Basin, and trans-Amazonian expansion through the Andean Corridor and across the Amazon river between Monte Alegre and Santarém. An antivenomic approach applied to assess the efficacy towards B. atrox venoms of two antivenoms raised in Costa Rica and Brazil using Bothrops venoms different than B. atrox in the immunization mixtures showed that both antivenoms immunodepleted very efficiently the major toxins (PIII-SVMPs, serine proteinases, CRISP, LAO) of paedomorphic venoms from Puerto Ayacucho (Venezuelan Amazonia) through S?o Bento, but had impaired reactivity towards PLA(2) and P-I SVMP molecules abundantly present in ontogenetic venoms. The degree of immunodepletion achieved suggests that each of these antivenoms may be effective against envenomations by paedomorphic, and some ontogenetic, B. atrox venoms. 相似文献
85.
In order to observe collagen and elastic fibers simultaneously, sections of human aorta, skin, lung, liver, and bladder were stained by Sirius red and analyzed by fluorescence microscopy. In all cases, the fibers of collagen presented the characteristic fluorescent red-orange color that results from the interaction of this extracellular protein with the dye, whereas elastic fibers showed strong green fluorescence (intrinsic fluorescence). This method efficiently detects collagen and elastic fibers when these two structures are present and could have valuable applications in processes that involves both fibers.L.F.B. received a doctoral fellowship from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil. 相似文献
86.
do C Borges NC Mendes GD Barrientos-Astigarraga RE Galvinas P Oliveira CH De Nucci G 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2005,827(2):165-172
An analytical method based on liquid chromatography with positive ion electrospray ionization (ESI) coupled to tandem mass spectrometry detection (LC-MS/MS) was developed for the determination of Verapamil in human plasma using Metoprolol as the internal standard. The analyte and internal standard were extracted from the plasma samples by liquid-liquid extraction and chromatographed on a C(8) analytical column. The mobile phase consisted of methanol-water (70:30; v/v)+12 mM formic acid. The method had a chromatographic total run time of 3.5 min and was linear within the range 1.00-500 ng/mL. Detection was carried out on a Micromass Quattro Ultima tandem mass spectrometer by multiple reaction monitoring (MRM). The intra-run imprecision was less than 5.1% calculated from the quality control (QC) samples, and 16.3% from the limit of quantification (LOQ). The accuracy determined from QC samples were between 92.9 and 103.1%, and 95.2 and 115.3% from LOQ. Concerning the inter-batch analysis, the imprecision was less than 5.8% and 17.3% from QC samples and LOQ, respectively. The accuracy varied between 98.2 and 100.8% from QC and it was 103.1% from LOQ. The protocol herein described was employed in a bioequivalence study of two tablet formulations of Verapamil. 相似文献
87.
Neco P Giner D Viniegra S Borges R Villarroel A Gutiérrez LM 《The Journal of biological chemistry》2004,279(26):27450-27457
Modified herpes virus (amplicons) were used to express myosin regulatory light chain (RLC) chimeras with green fluorescent protein (GFP) in cultured bovine chromaffin cells to study myosin II implication in secretion. After infection, RLC-GFP constructs were clearly identified in the cytoplasm and accumulated in the cortical region, forming a complex network that co-localized with cortical F-actin. Cells expressing wild type RLC-GFP maintained normal vesicle mobility, whereas cells expressing an unphosphorylatable form (T18A/S19A RLC-GFP) presented severe restrictions in granule movement as measured by individual tracking in dynamic confocal microscopy studies. Interestingly, the overexpression of this mutant form of RLC also affected the initial secretory burst elicited by either high K(+) or BaCl(2), as well as the secretion induced by fast release of calcium from caged compounds in individual cells. Moreover, T18A/S19A RLC-GFP-infected cells presented slower fusion kinetics of individual granules compared with controls as measured by analysis of amperometric spikes. Taken together, our results demonstrate the implication of myosin II in the transport of vesicles, and, surprisingly, in the final phases of exocytosis involving transitions affecting the activity of docked granules, and therefore uncovering a new role for this cytoskeletal element. 相似文献
88.
Borges N Marugg JD Empadinhas N da Costa MS Santos H 《The Journal of biological chemistry》2004,279(11):9892-9898
Rhodothermus marinus responds to fluctuations in the growth temperature and/or salinity by accumulating mannosylglycerate (MG). Two alternative pathways for the synthesis of MG have been identified in this bacterium: a single-step pathway and a two-step pathway. In this work, the genetic and biochemical characterization of the two-step pathway was carried out with the goal of understanding the function of the two pathways and their regulatory mechanisms. Mannosyl-3-phosphoglycerate synthase (MPGS) of the two-step pathway was purified from R. marinus. Sequence information led to the isolation of two contiguous genes, mpgs (encoding MPGS) and mpgp (encoding mannosyl-3-phosphoglycerate phosphatase). The recombinant MPGS had a low specific activity compared with other homologous MPGSs and contained approximately 30 additional residues at the C terminus. Truncation of this extension produced a protein with a 10-fold higher specific activity. Moreover, the activity of the complete MPGS was enhanced upon incubation with R. marinus cell extracts, and protease inhibitors abolished activation. Therefore, the C-terminal peptide of MPGS was identified as a regulatory site for short term control of MG synthesis in R. marinus. The control of gene expression by heat and osmotic stress was also studied; the level of mannosylglycerate synthase involved in the single-step pathway was selectively enhanced by heat stress, whereas MPGS was overproduced in response to osmotic stress. The concomitant changes in the level of MG were assessed as well. We conclude that the two alternative pathways for the synthesis of MG are differently regulated at the level of expression to play specific roles in the adaptation of R. marinus to two different types of aggression. This is the only example of pathway multiplicity being rationalized in terms of the need to respond efficiently to distinct environmental stresses. 相似文献
89.
90.
CTLA-4 blockage increases resistance to infection with the intracellular protozoan Trypanosoma cruzi
Martins GA Tadokoro CE Silva RB Silva JS Rizzo LV 《Journal of immunology (Baltimore, Md. : 1950)》2004,172(8):4893-4901
Recent studies have revealed an important role for CTLA-4 as a negative regulator of T cell activation. In the present study, we evaluated the importance of CTLA-4 to the immune response against the intracellular protozoan, Trypanosoma cruzi, the causative agent of Chagas' disease. We observed that the expression of CTLA-4 in spleen cells from naive mice cultured in the presence of live trypomastigote forms of T. cruzi increases over time of exposure. Furthermore, spleen cells harvested from recently infected mice showed a significant increase in the expression of CTLA-4 when compared with spleen cells from noninfected mice. Blockage of CTLA-4 in vitro and/or in vivo did not restore the lymphoproliferative response decreased during the acute phase of infection, but it resulted in a significant increase of NO production in vivo and in vitro. Moreover, the production of IFN-gamma in response to parasite Ags was significantly increased in spleen cells from anti-CTLA-4-treated infected mice when compared with the production found in cells from IgG-treated infected mice. CTLA-4 blockade in vivo also resulted in increased resistance to infection with the Y and Colombian strains of T. cruzi. Taken together these results indicate that CTLA-4 engagement is implicated in the modulation of the immune response against T. cruzi by acting in the mechanisms that control IFN-gamma and NO production during the acute phase of the infection. 相似文献