Showing papers by "Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto published in 2010"
TL;DR: The identification of [(+)-7-iso-JA-L-Ile] as the active biological hormonal form of jasmonate fills the greatest gap in knowledge about the signaling mechanism that is responsible for the activation of downstream genes in the jasMonate-signaling cascade.
Abstract: The plant hormones jasmonic acid and methyl jasmonate, along with their intermediate compounds, produced in the octadecanoid pathway, are important signaling molecules that are collectively called jasmonates. These are widespread in the plant kingdom and play crucial roles in biotic/abiotic stress responses, as well as in processes related to plant growth and development. Recently, it has been shown that jasmonates are also involved in reproductive processes. We present the most recent findings related to the biosynthesis, regulation and signaling mechanisms of jasmonates. Additionally, we discuss the identification of [(+)-7-iso-JA-L-Ile] as the active biological hormonal form of jasmonate; this fills the greatest gap in our knowledge about the signaling mechanism that is responsible for the activation of downstream genes in the jasmonate-signaling cascade. The identification of several Arabidopsis thaliana mutants was crucial to the elucidation of the signaling mechanisms involved in jasmonate-mediated responses. Finally, the involvement of jasmonates in the reproductive process of Nicotiana tabacum L. is briefly discussed, since some of the main enzymes of the jasmonic acid biosynthesis pathway were identified in a stigma/style expressed sequence tag database (TOBEST) of this Solanaceae species.
213 citations
TL;DR: A high linkage disequilibrium among the variation sites was detected, especially among the 14-bp insertion and the alleles +3142G and +3187A, all previously associated with low mRNA availability, demonstrating that their effects are not independent.
Abstract: The genetic structure of 3′untranslated region of the HLA-G gene: polymorphisms and haplotypes
195 citations
TL;DR: The results suggest that the antimicrobial activity of the extract from the leaves of R. officinalis may be ascribed mainly to the action of 2 and 3.
Abstract: The in vitro inhibitory activity of crude EtOH/H2O extracts from the leaves and stems of Rosmarinus officinalis L. was evaluated against the following microorganisms responsible for initiating dental caries: Streptococcus mutans, S. salivarius, S. sobrinus, S. mitis, S. sanguinis, and Enterococcus faecalis. Minimum inhibitory concentrations (MIC) were determined with the broth microdilution method. The bioassay-guided fractionation of the leaf extract, which displayed the higher antibacterial activity than the stem extract, led to the identification of carnosic acid (2) and carnosol (3) as the major compounds in the fraction displaying the highest activity, as identified by HPLC analysis. Rosmarinic acid (1), detected in another fraction, did not display any activity against the selected microorganisms. HPLC Analysis revealed the presence of low amounts of ursolic acid (4) and oleanolic acid (5) in the obtained fractions. The results suggest that the antimicrobial activity of the extract from the leaves of R. officinalis may be ascribed mainly to the action of 2 and 3.
171 citations
TL;DR: The results indicate that the DRB profile of NMO patients is different from that observed for MS patients, further corroborating the distinction between NMO and MS.
Abstract: Until recently, neuromyelitis optica (NMO) was considered to be a sub-type of multiple sclerosis (MS), which has a strong predilection for Caucasian populations, whereas NMO is more frequent in non-Caucasian individuals. The objective of this study was to compare the HLA-DRB profile in Brazilian Mulatto patients with NMO spectrum disorders (NMOSDs) with that observed for Mulatto MS patients and healthy Mulatto controls. Twenty seven NMOSD patients (20 women), all seropositive for NMO-IgG, 29 MS patients and 28 Mulatto healthy blood donors were evaluated for HLA-DRB allele groups. HLA-DRB1*03 allele group was overrepresented in NMO patients compared with healthy controls (p = 0.0401; OR = 3.23, 95%CI: 1.07-9.82). In contrast, the HLA-DRB1*15 allele group was overrepresented in Brazilian MS patients (OR = 15.89, 95%CI: 3.51-71.85; p < 0.0001). DRB3 was overrepresented in NMO (p = 0.0064), and DRB5 overrepresented in MS patients (p = 0.0001). The low frequency of HLA-DRB1*15 alleles was associated with the presence of long and central cord lesions at magnetic resonance. In addition, DRB1*15 alleles were associated with the fulfillment of the Barkhof criteria. In conclusion, these results indicate that the DRB profile of NMO patients is different from that observed for MS patients, further corroborating the distinction between NMO and MS.
130 citations
TL;DR: A deterministic partially self-avoiding walk (tourist walk) is presented, which provides a novel method for texture feature extraction and a new strategy, based on histograms, to extract information from its joint probability distribution is presented.
103 citations
TL;DR: Results indicate that Amlac2 expression is controlled by ecdysteroids and has a critical role in the differentiation of the adult exoskeleton of honey bees.
95 citations
TL;DR: In this paper, the authors explored the hexamerin genes found in the honey bee genome by exploring their structural characteristics, expression profiles, evolution, and functions in the life cycle of workers, drones and queens.
Abstract: Background
Hexamerins are hemocyanin-derived proteins that have lost the ability to bind copper ions and transport oxygen; instead, they became storage proteins. The current study aimed to broaden our knowledge on the hexamerin genes found in the honey bee genome by exploring their structural characteristics, expression profiles, evolution, and functions in the life cycle of workers, drones and queens.
91 citations
TL;DR: A mycelial β-glucosidase from the thermophilic mold Humicola insolens was purified and biochemically characterized in this paper, and the enzyme showed carbohydrate content of 21% and apparent molecular mass of 94 kDa, as estimated by gel filtration.
78 citations
TL;DR: A multigene phylogenetic approach based on nuclear, mitochondrial, and ribosomal loci, coupled with molecular clock methods, is implemented to elucidate the phylogenetic relationships and antiquity of subgenera and species of Melipona.
76 citations
TL;DR: Changes in Na+/K+- and V-ATPase activities and in mRNA expression appear to underpin ion uptake and Cl– secretion by the palaemonid shrimp gill.
Abstract: We evaluate osmotic and chloride (Cl(-)) regulatory capability in the diadromous shrimp Macrobrachium amazonicum, and the accompanying alterations in hemolymph osmolality and [Cl(-)], gill Na(+)/K(+)-ATPase activity, and expression of gill Na(+)/K(+)-ATPase α-subunit and V-ATPase B subunit mRNA during salinity (S) acclimation. We also characterize V-ATPase kinetics and the organization of transport-related membrane systems in the gill epithelium. Macrobrachium amazonicum strongly hyper-regulates hemolymph osmolality and [Cl(-)] in freshwater and in salinities up to 25‰ S. During a 10-day acclimation period to 25‰ S, hemolymph became isosmotic and hypo-chloremic after 5 days, [Cl(-)] alone remaining hyporegulated thereafter. Gill Na(+)/K(+)-ATPase α-subunit mRNA expression increased 6.5 times initial values after 1 h, then decreased to 3 to 4 times initial values by 24 h and to 1.5 times initial values after 10 days at 25‰ S. This increased expression was accompanied by a sharp decrease at 5 h then recovery of initial Na(+)/K(+)-ATPase activity within 24 h, declining again after 5 days, which suggests transient Cl(-) secretion. V-ATPase B-subunit mRNA expression increased 1.5-fold within 1 h, then reduced sharply to 0.3 times initial values by 5 h, and remained unchanged for the remainder of the 10-day period. V-ATPase activity dropped sharply and was negligible after a 10-day acclimation period to 21‰ S, revealing a marked downregulation of ion uptake mechanisms. The gill epithelium consists of thick, apical pillar cell flanges, the perikarya of which are coupled to an intralamellar septum. These two cell types respectively exhibit extensive apical evaginations and deep membrane invaginations, both of which are associated with numerous mitochondria, characterizing an ion transporting epithelium. These changes in Na(+)/K(+)- and V-ATPase activities and in mRNA expression during salinity acclimation appear to underpin ion uptake and Cl(-) secretion by the palaemonid shrimp gill.
74 citations
TL;DR: Results confirmed that the studied enzyme was an α-amylase ((1→4)-α-glucan glucanohydrolase), which was activated mainly by calcium and cobalt, and it presented as a glycoprotein with 23% carbohydrate content.
TL;DR: Photodynamic therapy-generated ROS inactivates A. actinomycetemcomitans both in planktonic and biofilm cultures, even in small concentrations of the photosensitizing agent, and it does not cause damage to fibroblast cells under the same conditions.
Abstract: Objective: To evaluate the inactivation of Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), responsible for causing aggressive periodontitis, using photodynamic therapy (PDT) by rose bengal (RB) as a model of a reactive oxygen species (ROS) generator, in planktonic and biofilm cultures. Materials and Methods: A. actinomycetemcomitans was grown in planktonic and biofilm cultures using tryptic soy broth medium. The sensibility (dark toxicity) to RB was determined, and its ideal concentration for PDT was established. Concentrations in the range from 0.01 to 50.0 μmol L−1 RB, with different light potencies and incubation times, were used. An odontological resin photopolymerizer that emits the adequate wavelength for absorption of the RB dye was applied. Bacterial viability was determined by colony- forming units (CFU). Results: RB photosensitizer dye in concentrations up to 0.1 μmol L−1 did not show toxicity per se toward A. actinomycetemcomitans cells. In a PDT study with photoirrad...
TL;DR: On the basis of analytical validation, it is shown that the MEPS/LC-UV methodology is adequate for antidepressant analysis, from therapeutic to toxic levels.
TL;DR: This tailoring approach is explored here, being heavily supported by the accumulated knowledge on the chemistry and photochemistry of ruthenium complexes, which allows NO donors/scavengers systems to be custom made designed.
Abstract: The discovery of the involvement of nitric oxide (NO) in several physiological and pathophysiological processes launched a spectacular increase in studies in areas such as chemistry, biochemistry, and pharmacology. As a consequence, the development of NO donors or scavengers for regulation of its concentration and bioavailability in vivo is required. In this sense, ruthenium nitrosyl ammines and aliphatic tetraazamacrocyles have attracted a lot of attention due to their unique chemical properties. These complexes are water soluble and stable in solution, not to mention that they can deliver NO when photochemically or chemically activated by the reduction of the coordinated nitrosonium (NO+). The tuning of the energies of the charge transfer bands, the redox potential, and the specific rate constants of NO liberation, in both solution and matrices, is desirable for the achievement of selective NO delivery to biological targets, hence making the ruthenium ammines and aliphatic tetraazamacrocyles a quite versatile platform for biological application purposes. These ruthenium nitrosyls have shown to be active in firing neurons in mouse hippocampus, performing redox reactions in mitochondria, acting in blood pressure control, exhibiting cytotoxic activities against trypanosomatids (T.cruzi and L.major) and tumor cells. This tailoring approach is explored here, being heavily supported by the accumulated knowledge on the chemistry and photochemistry of ruthenium complexes, which allows NO donors/scavengers systems to be custom made designed.
TL;DR: It is shown that efficient distinction between cutaneous leishmaniasis and Chagas' disease can be obtained with a low-cost biosensor system made with nanostructured films containing specific Leishmania amazonensis and T. cruzi antigens and employing impedance spectroscopy as the detection method.
Abstract: The need for reliable, fast diagnostics is closely linked to the need for safe, effective treatment of the so-called “neglected” diseases. The list of diseases with no field-adapted diagnostic tools includes leishmaniasis, shigella, typhoid, and bacterial meningitis. Leishmaniasis, in particular, is a parasitic disease caused by Leishmania spp. transmitted by infected phlebotomine sandfly, which remains a public health concern in developing countries with ca. 12 million people infected and 350 million at risk of infection. Despite several attempts, methods for diagnosis are still noneffective, especially with regard to specificity due to false positives with Chagas’ disease caused by Trypanosoma cruzi. Accepted golden standards for detecting leishmaniasis involve isolation of parasites either microscopically, or by culture, and in both methods specimens are obtained by invasive means. Here, we show that efficient distinction between cutaneous leishmaniasis and Chagas’ disease can be obtained with a low-co...
TL;DR: The effectiveness of the proposed SBSE/LC method was proven for analysis of commercial cosmetic products such as bodycreams, antiperspirant creams, and sunscreens.
Abstract: A sensitive and precise stir bar sorptive extraction (SBSE) combined with LC (SBSE/LC) analysis is described for simultaneous determination of methyl, ethyl, propyl, and butyl parabens in commercial cosmetic products in agreement with the European Union Cosmetics Directive 76/768/EEC. Important factors in the optimization of SBSE efficiency are discussed, such as time and temperature of extraction, pH, and ionic strength of the sample, matrix effects, and liquid desorption conditions by different modes (magnetic stirring, ultrasonic). The LOQs of the SBSE/LC method ranged from 30 to 200 ng/mg, with linear response over a dynamic range, from the LOQ to 2.5 microg/mg, with a coefficient of determination higher than 0.993. The interday precision of the SBSE/LC method presented a coefficient of variation lower than 5%. The effectiveness of the proposed method was proven for analysis of commercial cosmetic products such as body creams, antiperspirant creams, and sunscreens.
TL;DR: NRC-loaded lipid carriers were developed and characterized to further explore its topical administration for applications such as skin cancer treatment and performed well enough at releasing and protecting NO degradation in vitro that it is a promising carrier for topical delivery of NO.
TL;DR: Si/BBD proved to be the best electrodic material for the direct electrooxidation of tannery wastewaters with higher current efficiency and higher energy consumption thanks to the increase in current density.
TL;DR: It is demonstrated that PDT presents an impact on gingival inflammatory phenomenon during chronic periodontitis and leads to a specific decrease of antigen-presenting cells populations according to the drug delivery system used.
Abstract: The aim of this study was to evaluate the effects of the photodynamic therapy (PDT) on the inflammatory infiltrate and on the collagen network organization in human advanced chronic periodontitis. Two different drug delivery systems (DDS) were tested (liposomes and nanoemulsions) to determine if the effects of PDT could differ according to the DDS used. Sixteen patients presenting two teeth with chronic advanced periodontitis and important tooth mobility with clinical indication of extraction were included in the group liposomes (group L, n =8 ) or in the group nanoemulsions (group N, n = 8) in order to compare the effects of each DDS. Seven days before extractions one tooth of each patient was treated with PDT using phthalocyanine derivatives as photosensitizers and the contralateral tooth was taken as control. In group L the density of gingival collagen fibers (66 ± 19%) was significantly increased (p < 0.02) when compared to controls (35 ± 21%). Concerning the antigen-presenting cells, PDT had differential effects depending on the drug delivery system; the number of macrophages was significantly decreased (p < 0.05) in group L while the number of Langerhans cells was significantly decreased in group N (p < 0.02). These findings demonstrate that PDT presents an impact on gingival inflammatory phenomenon during chronic periodontitis and leads to a specific decrease of antigen-presenting cells populations according to the drug delivery system used.
TL;DR: The results of electron spin resonance (ESR) dating in eleven fossil teeth of three extinct taxa (Toxodon platensis, Stegomastodon waringi and Hippidion principale ) collected along Chui Creek and nearshore continental shelf, in an attempt to assess more accurately the ages of the fossils and its deposits are presented in this article.
TL;DR: Results show that ERY is more efficient at killing bacterial cells of A. actinomycetemcomitans in planktonic and biofilm culture compared with MB, suggesting that PDT using MB or ERY as a photosensitizing agent and odontologic resin photopolymerizer as a light source could be an efficient option for pocket decontamination in aggressive periodontal disease.
Abstract: Aim: The proposal of this work was to test the efficacy of photodynamic therapy (PDT) by using methylene blue (MB) and erythrosine (ERY) to inactivate Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), the main pathogen in aggressive periodontitis. Methods: A. actinomycetemcomitans was cultivated in planktonic cultures and biofilm by using Tryptic Soy Broth medium. The sensibility (dark toxicity) to MB and ERY was determined, and its ideal concentration for PDT protocols was established. An odontologic resin photopolymerizer was used as the light source. The bacterial viability was determined by CFU (planktonic cultures) and microscopic observation (biofilms). Results: The results show that ERY is more efficient at killing bacterial cells of A. actinomycetemcomitans in planktonic (75%) and biofilm (77%) culture compared with MB (50% and 54%, respectively). Conclusion: PDT using MB or ERY as a photosensitizing agent and odontologic resin photopolymerizer as a light source could be a...
TL;DR: A transcriptional profiling analysis of the A. fumigatus ΔAfcrzA mutant strain exposed to calcium stress provided an excellent opportunity to identify genes and pathways that are under the influence of AfCrzA.
Abstract: Background: Calcineurin, a serine/threonine-specific protein phosphatase, plays an important role in the control of cell morphology and virulence in fungi. Calcineurin regulates localization and activity of a transcription factor called CRZ1. Recently, we characterize Aspergillus fumigatus CRZ1 homologue, AfCrzA. Here, we investigate which pathways are influenced by A. fumigatus AfCrzA during a short pulse of calcium by comparatively determining the transcriptional profile of A. fumigatus wild type and ΔAfcrzA mutant strains. Results: We were able to observe 3,622 genes modulated in at least one timepoint in the mutant when compared to the wild type strain (3,211 and 411 at 10 and 30 minutes, respectively). Decreased mRNA abundance in the ΔcrzA was seen for genes encoding calcium transporters, transcription factors and genes that could be directly or indirectly involved in calcium metabolism. Increased mRNA accumulation was observed for some genes encoding proteins involved in stress response. AfCrzA overexpression in A. fumigatus increases the expression of several of these genes. The deleted strain of one of these genes, AfRcnA, belonging to a class of endogenous calcineurin regulators, calcipressins, had more calcineurin activity after exposure to calcium and was less sensitive to menadione 30 μM, hydrogen peroxide 2.5 mM, EGTA 25 mM, and MnCl2 25 mM. We constructed deletion, overexpression, and GFP fusion protein for the closely related A. nidulans AnRcnA. GFP::RcnA was mostly detected along the germling, did not accumulate in the nuclei and its location is not affected by the cellular response to calcium chloride. Conclusion: We have performed a transcriptional profiling analysis of the A. fumigatus ΔAfcrzA mutant strain exposed to calcium stress. This provided an excellent opportunity to identify genes and pathways that are under the influence of AfCrzA. AfRcnA, one of these selected genes, encodes a modulator of calcineurin activity. Concomitantly with A. fumigatus AfrcnA molecular analysis, we decided to exploit the conserved features of A. nidulans calcineurin system and investigated the A. nidulans AnRcnA homologue. A. nidulans AnRcnA mutation is suppressing CnaA mutation and it is responsible for modulating the calcineurin activity and mRNA accumulation of genes encoding calcium transporters.
TL;DR: The cranial anatomy of the rhynchosaur previously known as Scaphonyx sulcognathus allows its assignment to a new genus Teyumbaita, suggesting that the group survived the end-Carnian extinction event.
Abstract: Detailed description of the cranial anatomy of the rhynchosaur previously known as Scaphonyx sulcognathus allows its assignment to a new genus Teyumbaita. Two nearly complete skulls and a partial skull have been referred to the taxon, all of which come from the lower part of the Caturrita Formation, Upper Triassic of Rio Grande do Sul, southern Brazil. Cranial autapomorphies of Teyumbaita sulcognathus include anterior margin of nasal concave at midline, prefrontal separated from the ascending process of the maxilla, palatal ramus of pterygoid expanded laterally within palatines, dorsal surface of exoccipital markedly depressed, a single tooth lingually displaced from the main medial tooth-bearing area of the maxilla, and a number of other characters (such as skull broader than long; a protruding orbital anterior margin; anguli oris extending to anterior ramus of the jugal; bar between the orbit and the lower temporal fenestra wider than 0·4 of the total orbital opening; mandibular depth reaching more than 25 of the total length) support its inclusion in Hyperodapedontinae. T. sulcognathus is the only potential Norian rhynchosaur, suggesting that the group survived the end-Carnian extinction event.
TL;DR: The SBSE/HP LC-UV proved to be adequate to the rifampicin analyses from therapeutic to toxic levels and was as effective as the LLE/HPLC-UV method.
TL;DR: A proteoliposome system as an osteoblast-derived matrix vesicle (MV) biomimetic to facilitate the study of the interplay of tissue-nonspecific alkaline phosphatase (TNAP) and NPP1 during catalysis of biomineralization substrates is established.
TL;DR: The results showed that cuticular hydrocarbon profiles of workers were composed of alkanes, alkenes and alkadienes that varied quantitatively and qualitatively according to function of workers in the colony.
TL;DR: An overview of the state of the art in enzymatic biofuel cells can be found in this article, where the authors discuss the latest papers in this field and present an outlook for future research in this area.
Abstract: The continuous increase in the search for alternative energy sources worldwide is pushing the demand for “clean” and efficient energy production processes. The concept of biofuel cell has been known since 1912 but only in 1964 that the first enzyme-based biofuel cell was described. Since then, this kind of device has been the target of many research teams worldwide. This device is an alternative to the fuel cells employing metal catalysts that is capable of converting chemical energy into electricity, with the advantage of using biological molecules as catalysts. This new technology offers several other advantages over traditional batteries, including the use of renewable and clean catalysts, reaction selectivity, fuel flexibility, and the ability to operate at milder temperature. Recent studies have demonstrated promising characteristics of these devices; however, despite the several advances in this area, some challenges still need to be faced. This manuscript aims to provide the reader with an overview of the state of the art in enzymatic biofuel cells by discussing the latest papers in this field and presenting an outlook for future research in this area.
TL;DR: Conformational analysis of two known DKPs showed that folded conformations were as energetically stable as the extended one.
TL;DR: This work provides the first experimental evidence that meliponine group foraging strategies, large colony sizes and aggressive behavior form a suite of traits that enable colonies to improve dominance of rich resources.
Abstract: Competition for floral resources is a key force shaping pollinator communities, particularly among social bees. The ability of social bees to recruit nestmates for group foraging is hypothesized to be a major factor in their ability to dominate rich resources such as mass-flowering trees. We tested the role of group foraging in attaining dominance by stingless bees, eusocial tropical pollinators that exhibit high diversity in foraging strategies. We provide the first experimental evidence that meliponine group foraging strategies, large colony sizes and aggressive behavior form a suite of traits that enable colonies to improve dominance of rich resources. Using a diverse assemblage of Brazilian stingless bee species and an array of artificial “flowers” that provided a sucrose reward, we compared species’ dominance and visitation under unrestricted foraging conditions and with experimental removal of group-foraging species. Dominance does not vary with individual body size, but rather with foraging group size. Species that recruit larger numbers of nestmates (Scaptotrigona aff. depilis, Trigona hyalinata, Trigona spinipes) dominated both numerically (high local abundance) and behaviorally (controlling feeders). Removal of group-foraging species increased feeding opportunities for solitary foragers (Frieseomelitta varia, Melipona quadrifasciata and Nannotrigona testaceicornis). Trigona hyalinata always dominated under unrestricted conditions. When this species was removed, T. spinipes or S. aff. depilis controlled feeders and limited visitation by solitary-foraging species. Because bee foraging patterns determine plant pollination success, understanding the forces that shape these patterns is crucial to ensuring pollination of both crops and natural areas in the face of current pollinator declines.
TL;DR: Using a partition assay, it is demonstrated that AmJHEH has a negligible role in JH degradation, which, in the honey bee, is thus performed primarily by JHE.