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41.
Emma Barroso Jaume del Valle David Porquet Ana M. Vieira Santos Laia Salvadó Rosalía Rodríguez-Rodríguez Patrícia Gutiérrez Marta Anglada-Huguet Jordi Alberch Antoni Camins Xavier Palomer Mercè Pallàs Liliane Michalik Walter Wahli Manuel Vázquez-Carrera 《生物化学与生物物理学报:疾病的分子基础》2013,1832(8):1241-1248
The role of peroxisome proliferator activator receptor (PPAR)β/δ in the pathogenesis of Alzheimer's disease has only recently been explored through the use of PPARβ/δ agonists. Here we evaluated the effects of PPARβ/δ deficiency on the amyloidogenic pathway and tau hyperphosphorylation. PPARβ/δ-null mice showed cognitive impairment in the object recognition task, accompanied by enhanced DNA-binding activity of NF-κB in the cortex and increased expression of IL-6. In addition, two NF-κB-target genes involved in β-amyloid (Aβ) synthesis and deposition, the β site APP cleaving enzyme 1 (Bace1) and the receptor for advanced glycation endproducts (Rage), respectively, increased in PPARβ/δ-null mice compared to wild type animals. The protein levels of glial fibrillary acidic protein (GFAP) increased in the cortex of PPARβ/δ-null mice, which would suggest the presence of astrogliosis. Finally, tau hyperphosphorylation at Ser199 and enhanced levels of PHF-tau were associated with increased levels of the tau kinases CDK5 and phospho-ERK1/2 in the cortex of PPARβ/δ?/? mice.Collectively, our findings indicate that PPARβ/δ deficiency results in cognitive impairment associated with enhanced inflammation, astrogliosis and tau hyperphosphorylation in the cortex. 相似文献
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Hillers Rodríguez R Madoz-Gúrpide A Tirapu Ustárroz J 《Revista espa?ola de geriatría y gerontología》2011,46(5):275-280
Capgras syndrome is the most prevalent of the delusional misidentification syndromes. It appears in both psychiatric illness and organic brain damage. Cognitive and neuropsychiatric models (lateralization and disconnection) have been proposed to explain the syndrome. From a neuropsychological point of view Capgras syndrome seems to be due to damage of bifrontal and right limbic and temporal regions. Memory, feeling of familiarity, monitoring of self and reality would be altered. All of these cause a failure to adequately integrate the information about emotions and facial recognition. Relative preservation of the left frontal lobe may be necessary for the development of delusional response. There does not seem to be a differential pattern as regards the aetiology, but there is a common underlying neuropsychiatric mechanism. Based on theoretic models, and clinics features, we propose a neuropsychological battery to assess the Capgras syndrome, that should be sensitive to the main expected deficits. 相似文献
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Inferring the evolutionary history of Mediterranean plant lineages from current genetic, distributional and taxonomic patterns is complex because of a number of palaeoclimatic and geological interconnected factors together with landscape heterogeneity and human influence. Therefore, choosing spatially simplified systems as study groups is a suitable approach. An amplified fragment length polymorphism (AFLP) study using two restriction enzyme combinations (EcoRI/MseI and KpnI/MseI) was carried out to estimate the structure of genetic variation throughout the range of Armeria pungens. This species has a West Iberian-Corso/Sardinian disjunct distribution on coastal sand-dune ecosystems. Bayesian, amova and genetic distance analyses of the AFLP data revealed the same distinguishable genetic groups, which do not match the main geographical disjunction. Corso-Sardinian populations were found to be genetically closer to southwest Portuguese than to those from the Gulf of Cadiz (the closest geographically). Eastwards long-distance dispersal is therefore invoked to explain this geographical disjunction. A GIS analysis based on bioclimatic envelope modelling aiming to characterize the current locations of A. pungens found strong similarities between the Portugal and Corsica-Sardinia sites and less so between these areas and the Gulf of Cadiz. This coincident pattern between AFLP and climatic data suggests that the geographical disjunction is better explained by climatic factors than by the likeliness of a stochastic dispersal event. Such a combined phylogeographical-GIS modelling approach proves to be enlightening in reconstructing the evolutionary history of plant species. 相似文献
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The trans-sialidase from Trypanosoma cruzi (TcTS), the agent of Chagas' disease, is a unique enzyme involved in mammalian host-cell invasion. Since T. cruzi is unable to synthesize sialic acids de novo, TcTS catalyzes the transfer of alpha-(2-->3)-sialyl residues from the glycoconjugates of the host to terminal beta-galactopyranosyl units present on the surface of the parasite. TcTS also plays a key role in the immunomodulation of the infected host. Chronic Chagas' disease patients elicit TcTS-neutralizing antibodies that are able to inhibit the enzyme. N-Glycolylneuraminic acid has been detected in T. cruzi, and the trans-sialidase was pointed out as the enzyme involved in its incorporation from host glycoconjugates. However, N-glycolylneuraminic acid alpha-(2-->3)-linked-containing oligosaccharides have not been analyzed as donors in the T. cruzi trans-sialidase reaction. In this paper we studied the ability of TcTS to transfer N-glycolylneuraminic acid from Neu5Gc(alpha2-->3)Gal(beta1-->4)GlcbetaOCH(2)CH(2)N(3) (1) and Neu5Gc(alpha2-->3)Gal(beta1-->3)GlcNAcbetaOCH(2)CH(2)N(3) (2) to lactitol, N-acetyllactosamine and lactose as acceptor substrates. Transfer from 1 was more efficient (50-65%) than from 2 (20-30%) for the three acceptors. The reactions were inhibited when the enzyme was preincubated with a neutralizing antibody. K(m) values were calculated for 1 and 2 and compared with 3'-sialyllactose using lactitol as acceptor substrate. Analysis was performed by high-performance anion-exchange (HPAEC) chromatography. A competitive transfer reaction of compound 1 in the presence of 3'-sialyllactose and N-acetyllactosamine showed a better transfer of Neu5Gc than of Neu5Ac. 相似文献
47.
María Alejandra Guerrero-Rubio Rosalía López-Llorca Paula Henarejos-Escudero Francisco García-Carmona Fernando Gandía-Herrero 《Microbial biotechnology》2019,12(5):993-1002
The recent interest in plant pigment betalains as bioactive compounds and chemopreventive agents has led to the search for a reliable and scalable process to obtain them. The cloning of the novel and efficient enzyme 4,5-DOPA-extradiol dioxygenase from Gluconacetobacter diazotrophicus in an expression vector, and the subsequent heterologous expression in Escherichia coli cultures has led to the start-up of a biotechnological production system of individual pigments. The aim of this study was to search for the optimal conditions for the production of betalamic acid in microbial factories and the scaled-up obtention of the derived pigments. Four different betaxanthins and two betacyanins were obtained after the addition of non-transformable amines and amino acids and their condensation with the betalamic acid produced by the dioxygenase. The scaled-up obtention and purification of betalains improved the yields of the previous methodologies reaching quantities by up to 150 mg of pure compounds. 相似文献
48.
Treviño MA Palomares O Castrillo I Villalba M Rodríguez R Rico M Santoro J Bruix M 《Protein science : a publication of the Protein Society》2008,17(2):371-376
Ole e 9 is an olive pollen allergen belonging to group 2 of pathogenesis-related proteins. The protein is composed of two immunological independent domains: an N-terminal domain (NtD) with 1,3-beta-glucanase activity, and a C-terminal domain (CtD) that binds 1,3-beta-glucans. We have determined the three-dimensional structure of CtD-Ole e 9 (101 amino acids), which consists of two parallel alpha-helices forming an angle of approximately 55 degrees , a small antiparallel beta-sheet with two short strands, and a 3-10 helix turn, all connected by long coil segments, resembling a novel type of folding among allergens. Two regions surrounded by aromatic residues (F49, Y60, F96, Y91 and Y31, H68, Y65, F78) have been localized on the protein surface, and a role for sugar binding is suggested. The epitope mapping of CtD-Ole e 9 shows that B-cell epitopes are mainly located on loops, although some of them are contained in secondary structural elements. Interestingly, the IgG and IgE epitopes are contiguous or overlapped, rather than coincident. The three-dimensional structure of CtD-Ole e 9 might help to understand the underlying mechanism of its biochemical function and to determine possible structure-allergenicity relationships. 相似文献
49.
Sandra R. Fuselli Susana B. García de la Rosa Martín J. Eguaras Rosalía Fritz 《World journal of microbiology & biotechnology》2008,24(10):2067-2072
Antimicrobial properties and chemical composition of four citrus fruit essential oils to control Paenibacillus larvae, the causal agent of American foulbrood disease (AFB) were determined. This honeybee larvae disease occurs throughout the
world and is found in many beekeeping areas of Argentina. Citrus fruit essential oils tested were those from grapefruit (Citrus paradisi), sweet orange (Citrus sinensis), mandarin (Citrus nobilis) and lemon (Citrus limon). The components of the essential oils were identified by SPME-GC/MS analysis. The antimicrobial activity of the oils against
P. larvae were determined by the broth microdilution method. Two way ANOVA tests for minimum inhibitory concentrations (MICs) data
and minimal bactericide concentrations (MBCs) data, indicated significant differences between the strains and the oils tested.
The antimicrobial assays showed that the oil of C. paradisi inhibited the bacterial strains at the lowest concentrations tested, MICs and MBCs averages of 385.0 mg/l and 770.0 mg/l,
respectively. This property could be attributed to the kind and percentage of the volatile components of the oil, like limonene
(69.9%) and myrcene (9.6%). The use of essential oils or their specific volatile components individually against pests related
to food provision may represent an alternative scope for the control of this serious disease because it does not leave toxic
chemical residues in honey nor in its by products. 相似文献
50.