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111.
Alexandre Alberto Tonin Aleksandro Schafer da Silva Maria Luiza Thorstenberg Lívia Gelain Castilhos Raqueli Teresinha Fran?a Daniela Bitencourt Rosa Leal Marta Maria Medeiros Frescura Duarte Fernanda Silveira Flores Vogel Mario Luiz de La Rue Sonia Terezinha dos Anjos Lopes 《The Korean journal of parasitology》2013,51(4):421-426
Several studies have shown the mechanisms and importance of immune responses against Toxoplasma gondii infection and the notable role of cholinesterases in inflammatory reactions. However, the association between those factors has not yet been investigated. Therefore, the aim of this study was to evaluate the acetylcholinesterase (AChE) activity in blood and lymphocytes and the activity of butyrylcholinesterase (BChE) in serum of rats experimentally infected with T. gondii during the acute phase of infection. For that, an in vivo study was performed with evaluations of AChE and BChE activities on days 5 and 10 post-infection (PI). The activity of AChE in blood was increased on day 5 PI, while in lymphocytes its activity was enhanced on days 5 and 10 PI (P<0.05). No significant difference was observed between groups regarding to the activity of BChE in serum. A positive (P<0.01) correlation was observed between AChE activity and number of lymphocytes. The role of AChE as an inflammatory marker is well known in different pathologies; thus, our results lead to the hypothesis that AChE has an important role in modulation of early immune responses against T. gondii infection. 相似文献
112.
Raquel Fonseca-Maldonado Davi Serradella Vieira Juliana Sanchez Alponti Eric Bonneil Pierre Thibault Richard John Ward 《The Journal of biological chemistry》2013,288(35):25522-25534
Protein glycosylation is a common post-translational modification, the effect of which on protein conformational and stability is incompletely understood. Here we have investigated the effects of glycosylation on the thermostability of Bacillus subtilis xylanase A (XynA) expressed in Pichia pastoris. Intact mass analysis of the heterologous wild-type XynA revealed two, three, or four Hex8–16GlcNAc2 modifications involving asparagine residues at positions 20, 25, 141, and 181. Molecular dynamics (MD) simulations of the XynA modified with various combinations of branched Hex9GlcNAc2 at these positions indicated a significant contribution from protein-glycan interactions to the overall energy of the glycoproteins. The effect of glycan content and glycosylation position on protein stability was evaluated by combinatorial mutagenesis of all six potential N-glycosylation sites. The majority of glycosylated enzymes expressed in P. pastoris presented increased thermostability in comparison with their unglycosylated counterparts expressed in Escherichia coli. Steric effects of multiple glycosylation events were apparent, and glycosylation position rather than the number of glycosylation events determined increases in thermostability. The MD simulations also indicated that clustered glycan chains tended to favor less stabilizing glycan-glycan interactions, whereas more dispersed glycosylation patterns favored stabilizing protein-glycan interactions. 相似文献
113.
Roberto Zenteno-Cuevas Francisco X Silva-Hernández Fabiola Mendoza-Damián Maria Dolores Ramírez-Hernández Karen Vázquez-Medina Lorena Widrobo-García Aremy Cuellar-Sanchez Raquel Mu?íz-Salazar Leonor Enciso-Moreno Lucia Monserrat Pérez-Navarro José Antonio Enciso-Moreno 《Memórias do Instituto Oswaldo Cruz》2013,108(6):718-723
Tuberculosis (TB) is an infectocontagious respiratory disease caused by members
of the Mycobacterium tuberculosis complex. A 7 base pair (bp)
deletion in the locus polyketide synthase
(pks)15/1 is described as polymorphic among members of the
M. tuberculosis complex, enabling the identification of
Euro-American, Indo-Oceanic and Asian lineages. The aim of this study was to
characterise this locus in TB isolates from Mexico. One hundred
twenty clinical isolates were recovered from the states of Veracruz and Estado
de Mexico. We determined the nucleotide sequence of a ± 400 bp fragment of the
locus pks15/1, while genotypic characterisation was
performed by spoligotyping. One hundred and fifty isolates contained the 7 bp
deletion, while five had the wild type locus. Lineages X (22%),
LAM (18%) and T (17%) were the most frequent; only three (2%) of the isolates
were identified as Beijing and two (1%) EAI-Manila. The wild type
pks15/1 locus was observed in all Asian lineage isolates
tested. Our results confirm the utility of locus pks15/1 as a
molecular marker for identifying Asian lineages of the M.
tuberculosis complex. This marker could be of great value in the
epidemiological surveillance of TB, especially in countries like Mexico, where
the prevalence of such lineages is unknown. 相似文献
114.
Gabriel Capella Machado Daniela Vanessa Moris Thales Domingos Arantes Luciane Regina Franciscone Silva Raquel Cordeiro Theodoro Rinaldo P?ncio Mendes Adriana Pardini Vicentini Eduardo Bagagli 《Memórias do Instituto Oswaldo Cruz》2013,108(5):637-643
We aimed to evaluate whether the occurrence of cryptic species of
Paracoccidioides brasiliensis, S1, PS2, PS3 and
Paracoccidioides lutzii, has implications in the
immunodiagnosis of paracoccidioidomycosis (PCM). Small quantities of the antigen
gp43 were found in culture filtrates of P. lutzii strains and
this molecule appeared to be more variable within P. lutzii
because the synonymous-nonsynonymous mutation rate was lower, indicating an
evolutionary process different from that of the remaining genotypes. The
production of gp43 also varied between isolates belonging to the same species,
indicating that speciation events are important, but not sufficient to fully
explain the diversity in the production of this antigen. The culture filtrate
antigen AgEpm83, which was obtained from a PS3 isolate, showed large quantities
of gp43 and reactivity by immunodiffusion assays, similar to the standard
antigen (AgB-339) from an S1 isolate. Furthermore, AgEpm83 was capable of
serologically differentiating five serum samples from patients from the Botucatu
and Jundiaí regions. These patients had confirmed PCM but, were non-reactive to
the standard antigen, thus demonstrating an alternative for serological
diagnosis in regions in which S1 and PS2 occur. We also emphasise that it is not
advisable to use a single antigen preparation to diagnose PCM, a disease that is
caused by highly diverse pathogens. 相似文献
115.
Raquel Lebrero Elisa Rodríguez Rebeca Pérez Pedro A. García-Encina Raúl Muñoz 《Applied microbiology and biotechnology》2013,97(10):4627-4638
The removal of hydrophobic volatile organic compounds (VOCs) still remains the main restriction in the biological treatment of odorous emissions due to mass transfer limitations. The addition of a non-aqueous phase to conventional biotrickling filters (BTF) may overcome this limitation by enhancing VOCs transport from the gas to the microorganisms. This study compared the long-term and transient performance of a one- (1P) and two-liquid phase (2P; with silicone oil as non-aqueous phase) BTFs for the removal of four VOCs (butanone, toluene, alpha-pinene, and hexane) at empty bed residence times (EBRT) ranging from 47 to 6 s. Removal efficiencies (RE) >96 % were obtained for butanone, toluene, and alpha-pinene in both bioreactors regardless of the EBRT, while higher hexane REs were recorded in the 2P-BTF (81–92 %) compared to the 1P-BTF (60–97 %). The two-phase system always showed a more consistent performance, being able to better withstand step VOC concentration increases and starvation periods, although it was more affected by liquid recycling shutdowns due to a reduced VOC mass transfer. The analysis of the microbial communities showed a high biodiversity and richness despite the low C source spectrum and high community evenness and richness. In this context, the presence of silicone oil mediated the development of a highly different phylogenetic composition of the communities. 相似文献
116.
Pollen morphology of 58 species from 17 putative genera of the tribe Atripliceae (Chenopodiaceae) was investigated using light (LM) and scanning electron microscopy (SEM). Morphological variation was analyzed based on a dense sampling of the subtribes Atriplicinae and Eurotiinae, including many of the species in the two largest genera: Atriplex and Obione. The pantoporate pollen grains of Atripliceae are characterized by their spheroidal or subspheroidal shape, flat or moderately vaulted mesoporia with 21–120 pores, tectum with 1–8 spinules and 5–28(?38) puncta per?µm2, and 1–13 ectexinous bodies bearing 1–7 spinules each. Taxonomic relevance of the most important pollen morphological characters is discussed (pollen diameter, pore number, pore diameter, interporal distance, spinule and puncta density and ratio, number of ectexinous bodies, and their spinules). Pollen morphological data support the exclusion of Suckleya from the tribe and the recognition of subtribe Eurotiinae, but suggest that it needs to be reviewed. Pollen does not support generic recognition of Atriplex, Neopreissia and Obione and infrageneric subdivisions as currently recognized, and suggests the need to review them. Smaller or monotypic genera, such as Axyris, Ceratocarpus, Endolepis, Krascheninnikovia, Microgynoecium, Proatriplex and Spinacia have distinctive pollen morphological characters that support their generic status. Grayia needs to be reevaluated; although its two species are distinct from all the other species in the study, there are notable differences between each of them, and this suggests they may not form a natural group. Multivariate techniques were employed to investigate if there are discrete patterns of variation within Atripliceae. Principal Component Analyses (PCA) weakly differentiates four groups based on variation in pore number, puncta density per?µm2, and ratio between spinule and puncta density per?µm2; species of Ceratocarpus, Haloxanthium, Krascheninnikovia, Manochlamys, Microgynoecium, Spinacia, and some species of Atriplex and Obione are isolated. Preliminary results indicate that pollen data are potentially useful in the classification of the tribe, and further studies will be of taxonomic value. 相似文献
117.
Zhenjian Lin Lenny Marett Ronald W. Hughen Malem Flores Imelda Forteza Mary Anne Ammon Gisela P. Concepcion Samuel Espino Baldomero M. Olivera Gary Rosenberg Margo G. Haygood Alan R. Light Eric W. Schmidt 《Bioorganic & medicinal chemistry letters》2013,23(17):4867-4869
The bacterium Gordonia sp. 647 W.R.1a.05 was cultivated from the venom duct of the cone snail, Conus circumcisus. The Gordonia sp. organic extract modulated the action potential of mouse dorsal root ganglion neurons. Assay-guided fractionation led to the identification of the new compound circumcin A (1) and 11 known analogs (2–12). Two of these compounds, kurasoin B (7) and soraphinol A (8), were active in a human norepinephrine transporter assay with Ki values of 2575 and 867 nM, respectively. No neuroactivity had previously been reported for compounds in this structural class. Gordonia species have been reproducibly isolated from four different cone snail species, indicating a consistent association between these organisms. 相似文献
118.
Baoming Ji Catherine A. Gehring Gail W. T. Wilson R. M. Miller Lluvia Flores‐Rentería Nancy Collins Johnson 《Molecular ecology》2013,22(9):2573-2587
Arbuscular mycorrhizal (AM) fungi are widespread root symbionts that often improve the fitness of their plant hosts. We tested whether local adaptation in mycorrhizal symbioses would shape the community structure of these root symbionts in a way that maximizes their symbiotic functioning. We grew a native prairie grass (Andropogon gerardii) with all possible combinations of soils and AM fungal inocula from three different prairies that varied in soil characteristics and disturbance history (two native prairie remnants and one recently restored). We identified the AM fungi colonizing A. gerardii roots using PCR amplification and cloning of the small subunit rRNA gene. We observed 13 operational taxonomic units (OTUs) belonging to six genera in three families. Taxonomic richness was higher in the restored than the native prairies with one member of the Gigaspora dominating the roots of plants grown with inocula from native prairies. Inoculum source and the soil environment influenced the composition of AM fungi that colonized plant roots. Correspondingly, host plants and AM fungi responded significantly to the soil–inoculum combinations such that home fungi often had the highest fitness and provided the greatest benefit to A. gerardii. Similar patterns were observed within the soil–inoculum combinations originating from two native prairies, where five sequence types of a single Gigaspora OTU were virtually the only root colonizers. Our results indicate that indigenous assemblages of AM fungi were adapted to the local soil environment and that this process occurred both at a community scale and at the scale of fungal sequence types within a dominant OTU. 相似文献
119.
Patricia L. Jones Michael J. Ryan Victoria Flores Rachel A. Page 《Proceedings. Biological sciences / The Royal Society》2013,280(1772)
Animals can use different sources of information when making decisions. Foraging animals often have access to both self-acquired and socially acquired information about prey. The fringe-lipped bat, Trachops cirrhosus, hunts frogs by approaching the calls that frogs produce to attract mates. We examined how the reliability of self-acquired prey cues affects social learning of novel prey cues. We trained bats to associate an artificial acoustic cue (mobile phone ringtone) with food rewards. Bats were assigned to treatments in which the trained cue was either an unreliable indicator of reward (rewarded 50% of the presentations) or a reliable indicator (rewarded 100% of the presentations), and they were exposed to a conspecific tutor foraging on a reliable (rewarded 100%) novel cue or to the novel cue with no tutor. Bats whose trained cue was unreliable and who had a tutor were significantly more likely to preferentially approach the novel cue when compared with bats whose trained cue was reliable, and to bats that had no tutor. Reliability of self-acquired prey cues therefore affects social learning of novel prey cues by frog-eating bats. Examining when animals use social information to learn about novel prey is key to understanding the social transmission of foraging innovations. 相似文献
120.
Dr Raquel Marin Cristina M. Ramírez Cristina M. Ramírez Miriam González Elena González-Muñoz 《Molecular membrane biology》2013,30(2):148-160
Voltage-dependent anion channel (VDAC) is a porin known by its role in metabolite transport across mitochondria and participation in apoptotic processes. Although traditionally accepted to be located within mitochondrial outer membrane, some data has also reported its presence at the plasma membrane level where it seems to participate in regulation of normal redox homeostasis and apoptosis. Here, exposure of septal SN56 and hippocampal HT22 cells to specific anti-VDAC antibodies prior to amyloid beta (Aβ) peptide was observed to prevent neurotoxicity. In these cell lines, we identified a VDAC form associated with the plasma membrane that seems to be particularly abundant in caveolae. The two membrane-related isoforms of estrogen receptor α (mERα) (80 and 67 kDa), known in SN56 cells to participate in estrogen-induced neuroprotection against Aβ injury, were also observed to be present in caveolae. Interestingly, we demonstrated for the first time that both VDAC and mERα interact at the plasma membrane of these neurons as well as in microsomal fractions of the corresponding murine septal and hippocampal tissues. These proteins were also shown to associate with caveolin-1, thereby corroborating their presence in caveolar microdomains. Taken together, these results suggest that VDAC-mERα association at the plasma membrane level may participate in the modulation of Aβ-induced cell death. 相似文献