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51.
Carla Andréa Avelar Pires Fernando Octávio Machado Jucá Neto Nahima Castelo de Albuquerque Geraldo Mariano Moraes Macedo Keila de Nazaré Madureira Batista Marília Brasil Xavier 《PLoS neglected tropical diseases》2015,9(6)
BackgroundLeprosy, caused by Mycobacterium leprae, can lead to scarring and deformities. Human immunodeficiency virus (HIV), a lymphotropic virus with high rates of replication, leads to cell death in various stages of infection. These diseases have major social and quality of life costs, and although the relevance of their comorbidity is recognized, several aspects are still not fully understood.Conclusions/SignificanceThis study used a large sample and makes a significant contribution to the clinical outcomes of patients in the reactive state with comorbid HIV and leprosy. The data indicate that these diseases, although concurrent, have independent courses. 相似文献
52.
Schofield DJ Pope AR Clementel V Buckell J Chapple SDj Clarke KF Conquer JS Crofts AM Crowther SR Dyson MR Flack G Griffin GJ Hooks Y Howat WJ Kolb-Kokocinski A Kunze S Martin CD Maslen GL Mitchell JN O'Sullivan M Perera RL Roake W Shadbolt SP Vincent KJ Warford A Wilson WE Xie J Young JL McCafferty J 《Genome biology》2007,8(11):R254-18
We have created a high quality phage display library containing over 1010 human antibodies and describe its use in the generation of antibodies on an unprecedented scale. We have selected, screened and sequenced over 38,000 recombinant antibodies to 292 antigens, yielding over 7,200 unique clones. 4,400 antibodies were characterized by specificity testing and detailed sequence analysis and the data/clones are available online. Sensitive detection was demonstrated in a bead based flow cytometry assay. Furthermore, positive staining by immunohistochemistry on tissue microarrays was found for 37% (143/381) of antibodies. Thus, we have demonstrated the potential of and illuminated the issues associated with genome-wide monoclonal antibody generation. 相似文献
53.
Oligogalacturonic acids (OGAs), derived from plant cell wall pectin, have
been implicated in a number of signal transduction pathways involved in
growth, development and defense responses of higher plants. This study
investigates the size range of OGAs capable of inducing ethylene synthesis
in tomato plants, and demonstrates that in contrast with many other
effects, only short chain OGAs are active. Oligomers across a range of DP
from 2-15 were separated and purified to homogeneity by QAE-Sephadex anion
exchange chromatography using a novel elution system. The OGAs were applied
to tomato plants and assayed for their ability to induce ethylene gas
release and changes in steady state levels of mRNA encoding the ethylene
forming enzyme aminocyclopropane-1-carboxylic acid oxidase (ACO). The study
demonstrated that only OGAs in the size range of DP4-6 were active both in
eliciting ACO expression and in the production of ethylene.
相似文献
54.
Siqueira-Júnior CL Jardim BC Urményi TP Vicente AC Hansen E Otsuki K da Cunha M Madureira HC de Carvalho DR Jacinto T 《Plant cell reports》2008,27(2):387-397
The induction of a chloroplast-localized 13-lipoxygenase (13-LOX) in passion fruit leaves in response to methyl jasmonate
(MeJa) was previously reported. Since allene oxide synthase (AOS) is a key cytochrome P450 enzyme in the oxylipin pathway
leading to AOS-derived jasmonates, the results above led in turn to an investigation of AOS in our model plant. Spectrophotometric
assays showed that 24 h exposure of MeJa caused a high increase in 13-hydroperoxy linolenic acid (13-HPOT) metabolizing activity
in leaf tissue. Western analysis using polyclonal antibodies against tomato AOS strongly indicate that, at least a part of
the 13-HPOT metabolizing capacity can be attributed to AOS activity. We cloned the cDNA from a novel AOS encoding gene from
passion fruit, named PfAOS. The 1,512 bp open reading frame of the AOS–cDNA codes a putative protein of 504 amino acid residues containing a chloroplast
target sequence. Database comparisons of the deduced amino acid sequence showed highest similarity with dicot AOSs. Immunocytochemistry
analysis showed the compartmentalization of AOS in chloroplasts of MeJa treated leaves, corroborating the predicted subcellular
localization. Northern analysis showed that AOS gene expression is induced in leaf tissue in response to mechanical wounding
and exposure to MeJa. In addition, such treatments caused an increase in papain inhibitor(s) in leaf tissue. Taken together,
these results indicate that PfAOS may play an important role in systemic wound response against chewing insect attack. Furthermore, it can be useful as
a tool for understanding the regulation of jasmonates biosynthesis in passion fruit. 相似文献
55.
Annexin A2 is an abundant cellular protein that is mainly localized in the cytoplasm and plasma membrane, however a small population has been found in the nucleus, suggesting a nuclear function for the protein. Annexin A2 possesses a nuclear export sequence (NES) and inhibition of the NES is sufficient to cause nuclear accumulation. Here we show that annexin A2 accumulates in the nucleus in response to genotoxic agents including gamma-radiation, UV radiation, etoposide and chromium VI and that this event is mediated by the nuclear export sequence of annexin A2. Nuclear accumulation of annexin A2 is blocked by the antioxidant agent N-acetyl cysteine (NAC) and stimulated by hydrogen peroxide (H2O2), suggesting that this is a reactive oxygen species dependent event. In response to genotoxic agents, cells depleted of annexin A2 show enhanced phospho-histone H2AX and p53 levels, increased numbers of p53-binding protein 1 nuclear foci and increased levels of nuclear 8-oxo-2′-deoxyguanine, suggesting that annexin A2 plays a role in protecting DNA from damage. This is the first report showing the nuclear translocation of annexin A2 in response to genotoxic agents and its role in mitigating DNA damage. 相似文献
56.
Background
In a number of species males damage females during copulation, but the reasons for this remain unclear. It may be that males are trying to manipulate female mating behaviour or their life histories. Alternatively, damage may be a side-effect of male-male competition. In the black scavenger or dung fly Sepsis cynipsea (Diptera: Sepsidae) mating reduces female survival, apparently because males wound females during copulation. However, this damage does not seem to relate to attempted manipulation of female reproduction by males. Here we tested the hypothesis that harming females during mating is an incidental by-product of characters favoured during pre-copulatory male-male competition. We assessed whether males and their sons vary genetically in their ability to obtain matings and harm females, and whether more successful males were also more damaging. We did this by ranking males' mating success in paired competitions across several females whose longevity under starvation was subsequently measured. 相似文献57.
A change in twist of actin provides the force for the extension of the acrosomal process in limulus sperm: the false-discharge reaction 总被引:1,自引:5,他引:1 下载免费PDF全文
One of the most spectacular motions is the generation of the acrosomal process in the limulus sperm. On contact with the egg, the sperm generates a 60-mum-long process that literally drills its way through the jelly surrounding the egg. This irresversible reaction takes only a few seconds. We suggested earlier that this motion is driven by a change in twist of the actin filaments comprising the acrosomal process. In this paper we analyze the so-called false discharge, a reversible reaction, in which the acrosomal filament bundle extends laterally from the base of the sperm and not anteriorly from the apex. Unlike the true discharge, which is straight, the false discharge is helical. Before extension, the filament bundle is coiled about the base of the sperm. In the coil, the bundle is not smoothly bent but consists of arms (straight segments) and elbows (corners) so that the coil looks like a 14-sided polygon. The extension of the false discharge works as follows: starting at the base of the bundle, the filaments change their twist which concomitantly changes the orientations of the elbows relative to each other; that is, in the coil, the elbows all like in a common plane, but after the change in twist, the plane of each elbow is rotated to be perpendicular to that of its neighbors. This change transforms the bundle from a compact coil into an extended left- handed helix. Because the basal end of the bundle is unconstrained, the extension is lateral. The true discharge works the same way but starts at the apical end of the bundle. The apical end, however, is constrained by its passage through the nuclear canal, which directs the extention anteriorly. Unlike the false discharge, during the true discharge the elbows are melted out, making the reaction irreversible. This study shows that rapid movement can be regenerated by actin without myosin and gives us insight into the molecular mechanism. 相似文献
58.
Evolution at the tip and base of the X chromosome in an African population of Drosophila melanogaster 总被引:1,自引:0,他引:1
Hitchhiking effects of advantageous mutations have been invoked to explain
reduced polymorphism in regions of low crossing-over in Drosophila. Besides
reducing DNA heterozygosity, hitchhiking effects should produce strong
linkage disequilibrium and a frequency spectrum skewed toward an excess of
rare polymorphisms (compared to the neutral expectation). We measured DNA
polymorphism in a Zimbabwe population of D. melanogaster at three loci,
yellow, achaete, and suppressor of forked, located in regions of reduced
crossing-over. Similar to previously published surveys of these genomic
regions in other populations, we observed low levels of nucleotide
variability. However, the frequency spectrum was compatible with a neutral
model, and there was abundant evidence for recombination in the history of
the yellow and ac genes. Thus, some aspects of the data cannot be accounted
for by a simple hitchhiking model. An alternative hypothesis, background
selection, might be compatible with the observed patterns of linkage
disequilibrium and the frequency spectrum. However, this model cannot
account for the observed reduction in nucleotide heterozygosity. Thus,
there is currently no satisfactory theoretical model for the data from the
tip and base of the X chromosome in D. melanogaster.
相似文献
59.
Variations of Mn,Fe and S concentrations in sediment pore waters of Ria Formosa at different time scales 总被引:2,自引:0,他引:2
M. Caetano M. J. Madureira C. Vale M. J. Bebianno M. L. Gonçalves 《Aquatic Ecology》1995,29(3-4):275-281
Intertidal sediments of Ria Formosa have been surveyed at different time scales. Pore water of short sediment cores was collected bimonthly at five stations, from May 1993 to June 1994, around low-tide. One location was studied intensively every 1.5 hour, during a 6-hour air-exposure period, and during 20 minutes (1, 5, 10 and 20 minutes) immediately after tidal water had inundated the sampling site. Determinations of vertical profiles of pH, Eh, water content, O2, total dissolved Mn (Mndiss), total dissolved Fe (Fediss) and inorganic sulphur [(HS–)t] were carried out in all samples. The results obtained indicate that daily variations of Mndiss, Fediss and (HS–)t concentrations appear to be superimposed to the seasonal ones. Probably, the renewal of the pore water at periods of tidal inundation causes advective transport of manganese and exchange of iron, between the pore water and the solid fraction of the sediment that masks seasonal fluctuations induced by temperature and organic matter input variations. 相似文献