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91.
Ana B. Fagundo Susana Jiménez-Murcia Cristina Giner-Bartolomé Mohammed Anisul Islam Rafael de la Torre Antoni Pastor Felipe F. Casanueva Ana B. Crujeiras Roser Granero Rosa Ba?os Cristina Botella Jose M. Fernández-Real Gema Frühbeck Javier Gómez-Ambrosi José M. Menchón Francisco J. Tinahones Fernando Fernández-Aranda 《PloS one》2015,10(6)
The prefrontal (PFC) and orbitofrontal cortex (OFC) appear to be associated with both executive functions and olfaction. However, there is little data relating olfactory processing and executive functions in humans. The present study aimed at exploring the role of olfaction on executive functioning, making a distinction between primary and more cognitive aspects of olfaction. Three executive tasks of similar difficulty were used. One was used to assess hot executive functions (Iowa Gambling Task-IGT), and two as a measure of cold executive functioning (Stroop Colour and Word Test-SCWT and Wisconsin Card Sorting Test-WCST). Sixty two healthy participants were included: 31 with normosmia and 31 with hyposmia. Olfactory abilities were assessed using the ‘‘Sniffin’ Sticks’’ test and the olfactory threshold, odour discrimination and odour identification measures were obtained. All participants were female, aged between 18 and 60. Results showed that participants with hyposmia displayed worse performance in decision making (IGT; Cohen’s-d = 0.91) and cognitive flexibility (WCST; Cohen’s-d between 0.54 and 0.68) compared to those with normosmia. Multiple regression adjusted by the covariates participants’ age and education level showed a positive association between odour identification and the cognitive inhibition response (SCWT-interference; Beta = 0.29; p = .034). The odour discrimination capacity was not a predictor of the cognitive executive performance. Our results suggest that both hot and cold executive functions seem to be associated with higher-order olfactory functioning in humans. These results robustly support the hypothesis that olfaction and executive measures have a common neural substrate in PFC and OFC, and suggest that olfaction might be a reliable cognitive marker in psychiatric and neurologic disorders. 相似文献
92.
Sandra Irene Pitta-Alvarez Ana María Giulietti 《In vitro cellular & developmental biology. Plant》1995,31(4):215-220
Summary
Brugmansia candida hairy roots, obtained by infection withAgrobacterium rhizogenes LBA 9402, exhibit, after subculturing in liquid media, a tendency towards dedifferentiation. It has been found that the following
strategies can be applied to inhibit this dedifferentiation and preserve normal root morphology: (a) lowering both the mineral
and sucrose concentration in the media employed so as to diminish osmotic stress (a condition to which these roots appear
to be particularly susceptible); (b) employing antiauxins in appropriate concentrations; and (c) maintaining the hairy roots
on solid media prior to use in production processes in liquid media. The first strategy suggested does not favor alkaloid
productivity, but in this case a two-step method could be attempted: biomass with normal root morphology could be obtained
in a first stage using low sucrose concentrations, and in a second stage, sucrose could be increased in order to achieve higher
productivity. In all the clones ofB. candida obtained, alkaloid production was biased towards scopolamine. 相似文献
93.
The centrosome linker component C‐Nap1 (encoded by CEP250) anchors filaments to centrioles that provide centrosome cohesion by connecting the two centrosomes of an interphase cell into a single microtubule organizing unit. The role of the centrosome linker during development of an animal remains enigmatic. Here, we show that male CEP250 −/− mice are sterile because sperm production is abolished. Premature centrosome separation means that germ stem cells in CEP250 −/− mice fail to establish an E‐cadherin polarity mark and are unable to maintain the older mother centrosome on the basal site of the seminiferous tubules. This failure prompts premature stem cell differentiation in expense of germ stem cell expansion. The concomitant induction of apoptosis triggers the complete depletion of germ stem cells and consequently infertility. Our study reveals a role for centrosome cohesion in asymmetric cell division, stem cell maintenance, and fertility. 相似文献
94.
95.
Joana L. A. Brás Victor D. Alves Ana Luísa Carvalho Shabir Najmudin José A. M. Prates Luís M. A. Ferreira David N. Bolam Maria Jo?o Rom?o Harry J. Gilbert Carlos M. G. A. Fontes 《The Journal of biological chemistry》2012,287(53):44394-44405
Protein-protein interactions play a pivotal role in a large number of biological processes exemplified by the assembly of the cellulosome. Integration of cellulosomal components occurs through the binding of type I cohesin modules located in a non-catalytic molecular scaffold to type I dockerin modules located at the C terminus of cellulosomal enzymes. The majority of type I dockerins display internal symmetry reflected by the presence of two essentially identical cohesin-binding surfaces. Here we report the crystal structures of two novel Clostridium thermocellum type I cohesin-dockerin complexes (CohOlpC-Doc124A and CohOlpA-Doc918). The data revealed that the two dockerins, Doc918 and Doc124A, are unusual because they lack the structural symmetry required to support a dual binding mode. Thus, in both cases, cohesin recognition is dominated by residues located at positions 11, 12, and 19 of one of the dockerin binding surfaces. The alternative binding mode is not possible (Doc918) or highly limited (Doc124A) because residues that assume the critical interacting positions, when dockerins are reoriented by 180°, make steric clashes with the cohesin. In common with a third dockerin (Doc258) that also presents a single binding mode, Doc124A directs the appended cellulase, Cel124A, to the surface of C. thermocellum and not to cellulosomes because it binds preferentially to type I cohesins located at the cell envelope. Although there are a few exceptions, such as Doc918 described here, these data suggest that there is considerable selective pressure for the evolution of a dual binding mode in type I dockerins that direct enzymes into cellulosomes. 相似文献
96.
The preparation of new palladium(II) and platinum(II) complexes derived from alpha-diphenyl ethanedione bis(thiosemicarbazone), 1, and alpha-diphenyl ethanedione bis(4-ethylthiosemicarbazone), 2, is described. The palladium complexes 3 and 4 and platinum complexes 5 and 6 have been characterized by elemental analyses, fast atom bombardment mass spectrometry (FAB(+)) and spectroscopic studies (IR, (1)HNMR). The crystal and molecular structures of the dimeric cyclopalladated compound 4 and the mononuclear platinum complex 6 have been determined by single crystal X-ray diffraction. The cytotoxic activity of the free ligands and palladium and platinum complexes against human A2780 and A2780cisR (acquired resistance to cisplatin) epithelial ovarian carcinoma cells lines is also reported. The IC(50) values for compounds 1, 5 and 6 were found to be higher than that of cisplatin but the maximum antiproliferative activity was similar. Furthermore, the compounds largely retain their activity in the A2780cisR cell line, having a much better resistance factor than cisplatin in the pair of cell lines tested. 相似文献
97.
Szerman N Schroh I Rossi AL Rosso AM Krymkiewicz N Ferrarotti SA 《Bioresource technology》2007,98(15):2886-2891
Cyclodextrins (CD) are cyclic oligosaccharides with multiple applications in the food, pharmaceutical, cosmetic, agricultural and chemical industries. In this work, the conditions used to produce CD with cyclodextrin glycosyltransferase from Bacillus circulans DF 9R were optimized using experimental designs. The developed method allowed the partial purification and concentration of the enzyme from the cultural broth and, subsequently, the CD production, using the same cassava starch as enzyme adsorbent and as substrate. Heat-treatment of raw starch at 70 degrees C for 15 min in the presence of adsorbed cyclodextrin glycosyltransferase allowed the starch liquefaction without enzyme inactivation. The optimum conditions for CD production were: 5% (w/v) cassava starch, 15 U of enzyme per gram of substrate, reaction temperature of 56 degrees C and pH 6.4. After 4h, the proportion of starch converted to CD reached 66% (w/w) and the weight ratio of alpha-CD:beta-CD:gamma-CD was 1.00:0.70:0.16. 相似文献
98.
Fernanda A. H. Batista Leandro S. Goto Wanius Garcia Derminda I. de Moraes Mario de Oliveira Neto Igor Polikarpov Marcia R. Cominetti Heloísa S. Selistre-de-Araújo Leila M. Beltramini Ana Paula Ulian Araújo 《European biophysics journal : EBJ》2010,39(8):1193-1205
Lectins have been classified into a structurally diverse group of proteins that bind carbohydrates and glycoconjugates with
high specificity. They are extremely useful molecules in the characterization of saccharides, as drug delivery mediators,
and even as cellular surface makers. In this study, we present camptosemin, a new lectin from Camptosema ellipticum. It was characterized as an N-acetyl-d-galactosamine-binding homo-tetrameric lectin, with a molecular weight around 26 kDa/monomers. The monomers were stable over
a wide range of pH values and exhibited pH-dependent oligomerization. Camptosemin promoted adhesion of breast cancer cells
and hemagglutination, and both activities were inhibited by its binding of sugar. The stability and unfolding/folding behavior
of this lectin was characterized using fluorescence and far-UV circular dichroism spectroscopies. The results indicate that
chemical unfolding of camptosemin proceeds as a two-state monomer-tetramer process. In addition, small-angle X-ray scattering
shows that camptosemin behaves as a soluble and stable homo-tetramer molecule in solution. 相似文献
99.
Graham L. Cromar Jonathan R. Epp Ana Popovic Yusing Gu Violet Ha Brandon J. Walters James St. Pierre Xuejian Xiong John G. Howland Sheena A. Josselyn Paul W. Frankland John Parkinson 《PLoS neglected tropical diseases》2022,16(7)
During chronic infection, the single celled parasite, Toxoplasma gondii, can migrate to the brain where it has been associated with altered dopamine function and the capacity to modulate host behavior, increasing risk of neurocognitive disorders. Here we explore alterations in dopamine-related behavior in a new mouse model based on stimulant (cocaine)-induced hyperactivity. In combination with cocaine, infection resulted in heightened sensorimotor deficits and impairment in prepulse inhibition response, which are commonly disrupted in neuropsychiatric conditions. To identify molecular pathways in the brain affected by chronic T. gondii infection, we investigated patterns of gene expression. As expected, infection was associated with an enrichment of genes associated with general immune response pathways, that otherwise limits statistical power to identify more informative pathways. To overcome this limitation and focus on pathways of neurological relevance, we developed a novel context enrichment approach that relies on a customized ontology. Applying this approach, we identified genes that exhibited unexpected patterns of expression arising from the combination of cocaine exposure and infection. These include sets of genes which exhibited dampened response to cocaine in infected mice, suggesting a possible mechanism for some observed behaviors and a neuroprotective effect that may be advantageous to parasite persistence. This model offers a powerful new approach to dissect the molecular pathways by which T. gondii infection contributes to neurocognitive disorders. 相似文献
100.
Ekaterini Blaveri Fiona Kelly Alessandra Mallei Kriss Harris Adam Taylor Juliet Reid Maria Razzoli Lucia Carboni Chiara Piubelli Laura Musazzi Girogio Racagni Aleksander Mathé Maurizio Popoli Enrico Domenici Stewart Bates 《PloS one》2010,5(9)