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1.
Olatz Arteaga Miren Revuelta Leyre Urigüen Antonia álvarez Haizea Montalvo Enrique Hilario 《PloS one》2015,10(11)
Despite advances in neonatal care, hypoxic-ischemic brain injury is still a serious clinical problem, which is responsible for many cases of perinatal mortality, cerebral palsy, motor impairment and cognitive deficits. Resveratrol, a natural polyphenol with important anti-oxidant and anti-inflammatory properties, is present in grapevines, peanuts and pomegranates. The aim of the present work was to evaluate the possible neuroprotective effect of resveratrol when administered before or immediately after a hypoxic-ischemic brain event in neonatal rats by analyzing brain damage, the mitochondrial status and long-term cognitive impairment. Our results indicate that pretreatment with resveratrol protects against brain damage, reducing infarct volume, preserving myelination and minimizing the astroglial reactive response. Moreover its neuroprotective effect was found to be long lasting, as behavioral outcomes were significantly improved at adulthood. We speculate that one of the mechanisms for this neuroprotection may be related to the maintenance of the mitochondrial inner membrane integrity and potential, and to the reduction of reactive oxygen species. Curiously, none of these protective features was observed when resveratrol was administered immediately after hypoxia-ischemia. 相似文献
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Georgia Vlahou Oxana Schmidt Bettina Wagner Handan Uenlue Petra Dersch Francisco Rivero Barbara A Weissenmayer 《BMC microbiology》2009,9(1):138-12
Background
All human pathogenic Yersinia species share a virulence-associated type III secretion system that translocates Yersinia effector proteins into host cells to counteract infection-induced signaling responses and prevent phagocytosis. Dictyostelium discoideum has been recently used to study the effects of bacterial virulence factors produced by internalized pathogens. In this study we explored the potential of Dictyostelium as model organism for analyzing the effects of ectopically expressed Yersinia outer proteins (Yops). 相似文献5.
Mousumi Bose Sriram Machineni Blanca Oliván Julio Teixeira James J. McGinty Baani Bawa Ninan Koshy Antonia Colarusso Blandine Laferrère 《Obesity (Silver Spring, Md.)》2010,18(6):1085-1091
The goal of this study was to understand the mechanisms of greater weight loss by gastric bypass (GBP) compared to gastric banding (GB) surgery. Obese weight‐ and age‐matched subjects were studied before (T0), after a 12 kg weight loss (T1) by GBP (n = 11) or GB (n = 9), and at 1 year after surgery (T2). peptide YY3–36 (PYY3–36), ghrelin, glucagon‐like peptide‐1 (GLP‐1), leptin, and amylin were measured after an oral glucose challenge. At T1, glucose‐stimulated GLP‐1 and PYY levels increased significantly after GBP but not GB. Ghrelin levels did not change significantly after either surgery. In spite of equivalent weight loss, leptin and amylin decreased after GBP, but not after GB. At T2, weight loss was greater after GBP than GB (P = 0.003). GLP‐1, PYY, and amylin levels did not significantly change from T1 to T2; leptin levels continued to decrease after GBP, but not after GB at T2. Surprisingly, ghrelin area under the curve (AUC) increased 1 year after GBP (P = 0.03). These data show that, at equivalent weight loss, favorable GLP‐1 and PYY changes occur after GBP, but not GB, and could explain the difference in weight loss at 1 year. Mechanisms other than weight loss may explain changes of leptin and amylin after GBP. 相似文献
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Antonia Eastwood Quentin C. B. Cronk Johannes C. Vogel Andreas Hemp Mary Gibby 《Plant Systematics and Evolution》2004,245(1-2):93-106
The endemic elaphoglossoid ferns, Elaphoglossum dimorphum, E. nervosum and Microstaphyla furcata of St Helena, form a closely related group within section Lepidoglossa when analysed phylogenetically using sequences from the chloroplast trnL intron (partial) and trnL-F intergenic spacer. Microstaphyla furcata, traditionally placed in its own genus, is clearly shown to belong to Elaphoglossum confirming the previous transfer of this species to Elaphoglossum as E. bifurcatum. There is hardly any trnL-F sequence divergence between the species, in fact sequences of E. nervosum and E.
dimorphum are identical. These results are consistent with the possible origin of E. dimorphum as a hybrid between E. bifurcatum and E. nervosum or with the view that the three species are the result of a recent radiation. The potential conflict between phylogenetic and morphological distinctness in determining species conservation priorities is discussed. 相似文献
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Alkylating agents often generate 3-methylcytosine (3meC) lesions that are efficiently repaired by AlkB homologues. If AlkB homologue proteins are not functional, or the number of 3meC lesions exceeds the cellular repair capacity, the damage will persist in the genome and become substrate of DNA polymerases (Pols). Though alkylating agents are present in our environment and used in the clinics, currently nothing is known about the impact of 3meC on the accuracy and efficiency of human Pols. Here we compared the 3meC bypass properties of six human Pols belonging to the three families: B (Pol δ), X (Pols β and λ) and Y (Pols κ, ι and η). We show that under replicative conditions 3meC impairs B-family, blocks X-family, but not Y-family Pols, in particular Pols η and ι. These Pols successfully synthesize opposite 3meC; Pol ι preferentially misincorporates dTTP and Pol η dATP. The most efficient extenders from 3meC base-paired primers are Pols κ and η. Finally, using xeroderma pigmentosum variant patient cell extracts, we provide evidence that the presence of functional Pol η is mandatory to efficiently overcome 3meC by mediating complete bypass or extension. Our data suggest that Pol η is crucial for efficient 3meC bypass. 相似文献
8.
Antonia Göhler Claudia Büchner Sabine André Sören Doose Herbert Kaltner Hans-Joachim Gabius 《Biochimie》2012
Spectroscopic monitoring is applied to detect structural alterations for homodimeric adhesion/growth-regulatory galectins. Mammalian galectin-1 and the avian ortholog CG-1B, due to their distinct patterns of cysteine positioning, can undergo oxidation. When monitoring tryptophan fluorescence anisotropy comparatively, an indicator of structural changes affecting rotational diffusion, segmental motion and/or fluorescence life time, reductions are seen in both cases upon oxidation. The decrease was especially marked for the human protein, more than 2-fold compared to the avian lectin. Using this approach to analyze binding of lactose, equilibrium and kinetic binding constants of both proteins were similar. This result is corroborated by fluorescence correlation spectroscopy with labeled proteins. Of note, the diffusion constant of CG-1B increased by 5.6% in the presence of lactose, as has been seen for the human protein. When processing the other two homodimeric avian galectins (CG-1A, CG-2) accordingly it was revealed that sequence homology does not translate into identical behavior. The diffusion constant of CG-1A was not affected, a slight decrease (−3.8%) was observed for CG-2. Obviously, alterations induced by oxidation and responses to ligand binding are different between these closely related proteins. Methodologically, the two spectroscopic techniques are proven to be sensitive and robust sensors for detecting intergalectin differences. 相似文献
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In diagnostic studies, a new diagnostic test is often compared with a standard test and both tests are applied on the same patients, called paired design. The true disease state is in general given by the so‐called gold standard (most reliable method for classification), which has to be known for all patients. The benefit of the new diagnostic test can be evaluated by sensitivity and specificity, which are in fact proportions. This means, for the comparison of two diagnostic tests, confidence intervals for the difference of the dependent estimated sensitivities and specificities are calculated. In the literature, many comparisons of different approaches can be found, but none explicitly for diagnostic studies. For this reason we compare 13 approaches for a set of scenarios that represent data of diagnostic studies (e.g., with sensitivity and specificity ?0.8). With simulation studies, we show that the nonparametric interval with normal approximation can be recommended for the difference of two dependent sensitivities or specificities without restriction, the Wald interval with the limitation of slightly anti‐conservative results for small sample sizes, and the nonparametric intervals with t‐approximation, and the Tango interval with the limitation of conservative results for high correlations. 相似文献